A, B and C start at the same time in the same direction to run around a circular stadium. A completes a round in 252 seconds, B in 308 seconds and C in 198 seconds, all starting at the same point. After what time will they meet again at the starting point? A.15 minutes 15 seconds B.42 minutes 30 seconds C.42 minutes D.46 minutes 12 seconds E.None of these

A, B and C start at the same time in the same direction to run around a circular stadium. A completes a round in 252 seconds, B in 308 seconds and C in 198 seconds, all starting at the same point. After what time will they meet again at the starting point? A.15 minutes 15 seconds B.42 minutes 30 seconds C.42 minutes D.46 minutes 12 seconds E.None of these
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Answer :

Answer – D (46 minutes 12 seconds) Explanation – L.C.M. of 252, 308 and 198 = 2772.So, A, B and C will again meet at the starting point in 2772 see i.e., 46 min. 12 sec
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Related questions

Six bells commence tolling together and toll at intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together? A.8 B.11 C.13 D.16 E.None of theseSix bells commence tolling together and toll at intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together? A.8 B.11 C.13 D.16 E.None of these

Description : Six bells commence tolling together and toll at intervals of 2, 4, 6, 8, 10 and 12 seconds respectively. In 30 minutes, how many times do they toll together? A.8 B.11 C.13 D.16 E.None of these

Last Answer : Answer – D (16) Explanation – L.C.M. of 2, 4, 6, 8, 10, 12 is 120.So, the bells will toll together after every 120 seconds, i.e, 2 minutes.In 30 minutes, they will toll together 30/2 + 1 = 16

The H.C.F. of two numbers is 11 and their L.C.M. is 7700. If one of the numbers is 275, then the other is: A.269 B.275 C.308 D.310 E.None of these

Description : The H.C.F. of two numbers is 11 and their L.C.M. is 7700. If one of the numbers is 275, then the other is: A.269 B.275 C.308 D.310 E.None of these

Last Answer : Answer – C (308) Explanation – Other number =[11 x 7700]/275 = 308

The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 8 is: A.534 B.486 C.544 D.548 E.None of these

Description : The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 8 is: A.534 B.486 C.544 D.548 E.None of these

Last Answer : Answer – D (548) Explanation – Required number = (L.C.M. of 12, 15, 20, 54) + 8 = 540 + 8 = 548.

The least number which should be added to 2497 so that the sum is exactly divisible by 5, 6, 4 and 3 is: A.10 B.14 C.23 D.30 E.None of these

Description : The least number which should be added to 2497 so that the sum is exactly divisible by 5, 6, 4 and 3 is: A.10 B.14 C.23 D.30 E.None of these

Last Answer : Answer – C (23) Explanation – L.C.M. of 5, 6, 4 and 3 = 60. On dividing 2497 by 60, the remainder is 37. Number to be added = (60 – 37) = 23

The L.C.M. of two numbers is 48. The numbers are in the ratio 2 : 3. Then sum of the number is: A.30 B.22 C.40 D.60 E.None of these

Description : The L.C.M. of two numbers is 48. The numbers are in the ratio 2 : 3. Then sum of the number is: A.30 B.22 C.40 D.60 E.None of these

Last Answer : Answer – C (40) Explanation – Let the numbers be 2x and 3x. Then, their L.C.M. = 6x. So, 6x = 48 or x = 8. The numbers are 16 and 24. Hence, required sum = (16 + 24) = 40.

The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is: A.68 B.98 C.180 D.364 E.None of these

Description : The least multiple of 7, which leaves a remainder of 4, when divided by 6, 9, 15 and 18 is: A.68 B.98 C.180 D.364 E.None of these

Last Answer : Answer – D (364) Explanation – L.C.M. of 6, 9, 15 and 18 is 90. Let required number be 90k + 4, which is multiple of 7. Least value of k for which (90k + 4) is divisible by 7 is k = 4. Required number = (90 x 4) + 4 = 364.

A,B are start walking around a Circular park of radius 70m. They start at the same point, and A goes clockwise at 10m/s, while b goes anti-clockwise at 20m/s.How many times will they cross each other at the starting point if they walk for 30 minutes? a) 20 b) 40 c) 60 d) 80 e) None of the above

Description : A,B are start walking around a Circular park of radius 70m. They start at the same point, and A goes clockwise at 10m/s, while b goes anti-clockwise at 20m/s.How many times will they cross each other at the starting point if they walk for 30 minutes? a) 20 b) 40 c) 60 d) 80 e) None of the above

Last Answer : Radius = 70m, So circumference = 2 (22/7) 70 =440m Relative speed = 10 +20 = 30m/s They will meet everytime at the starting point when the distance covered by both put together is a multiple of 440 ... =1800/44 =40.9 So they will meet 40 times (we need to ignore the decimal part). Answer : b

A,B are start walking around a Circular park of radius 70m. They start at the same point, and A goes clockwise at 10m/s, while b goes anti-clockwise at 20m/s.How many times will they cross each other at the starting point if they walk for 30 minutes? a) 20 b) 40 c) 60 d) 80 e) None of the above

Description : A,B are start walking around a Circular park of radius 70m. They start at the same point, and A goes clockwise at 10m/s, while b goes anti-clockwise at 20m/s. How many times will they cross each other at the starting point if they walk for 30 minutes? a) 20 b) 40 c) 60 d) 80 e) None of the above

Last Answer : Radius = 70m, So circumference = 2 (22/7) 70 =440m Relative speed = 10 +20 = 30m/s They will meet everytime at the starting point when the distance covered by both put together is a multiple of 440 ... =1800/44 =40.9 So they will meet 40 times (we need to ignore the decimal part). Answer : b

There is a circular path around a sports field. Priya takes 18 minutes to drive one round of the field. Harish takes 12 minutes. Suppose they both start at the same point and at the same time and go in the same direction. After how many minutes will they meet ? (a) 36 minutes (b) 18 minutes (c) 6 minutes (d) They will not meet

Description : There is a circular path around a sports field. Priya takes 18 minutes to drive one round of the field. Harish takes 12 minutes. Suppose they both start at the same point and at the same time and go in the same ... will they meet ? (a) 36 minutes (b) 18 minutes (c) 6 minutes (d) They will not meet

Last Answer : (a) 36 minutes

The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is: A.1 B.2 C.3 D.5 E.None of these

Description : The product of two numbers is 2028 and their H.C.F. is 13. The number of such pairs is: A.1 B.2 C.3 D.5 E.None of these

Last Answer : Answer – B (2) Explanation – Let the numbers 13a and 13b. Then, 13a x 13b = 2028 ab = 12. Now, the co-primes with product 12 are (1, 12) and (3, 4).

The product of two numbers is 4107. If the H.C.F. of these numbers is 37, then the greater number is: A.124 B.100 C.111 D.175 E.None of these

Description : The product of two numbers is 4107. If the H.C.F. of these numbers is 37, then the greater number is: A.124 B.100 C.111 D.175 E.None of these

Last Answer : Answer – C (111) Explanation – Let the numbers be 37a and 37b. Then, 37a x 37b = 4107 ab = 3. Now, co-primes with product 3 are (1, 3). So, the required numbers are (37 x 1, 37 x 3) i.e., (37, 111). Greater number = 111.

The least number, which when divided by 48, 60, 72, 108 and 140 leaves 38, 50, 62, 98 and 130 as remainders respectively, is: A.11115 B.15110 C.15130 D.15310 E.None of these

Description : The least number, which when divided by 48, 60, 72, 108 and 140 leaves 38, 50, 62, 98 and 130 as remainders respectively, is: A.11115 B.15110 C.15130 D.15310 E.None of these

Last Answer : Answer – B (15110) Explanation – Here (48 – 38) = 10, (60 – 50) = 10, (72 – 62) = 10, (108 – 98) = 10 & (140 – 130) = 10. Required number = (L.C.M. of 48, 60, 72, 108, 140) – 10 = 15120 – 10 = 15110

How many students studying Dentistry know only either English or Hindi? (1) 166 (2) 162 (3) 308 (4) 198 (5) 248

Description : How many students studying Dentistry know only either English or Hindi? (1) 166 (2) 162 (3) 308 (4) 198 (5) 248

Last Answer : 4) 198

A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.? A.15 B.8 C.7 D.10 E.None of these

Description : A and B walk around a circular track. They start at 8 a.m. from the same point in the opposite directions. A and B walk at a speed of 2 rounds per hour and 3 rounds per hour respectively. How many times shall they cross each other before 9.30 a.m.? A.15 B.8 C.7 D.10 E.None of these

Last Answer : Answer – C (7) Explanation – Relative speed = (2 + 3) = 5 rounds per hourSo, they cross each other 5 times in an hour and 2 times in half an hourHence, they cross each other 7 times before 9.30 a.m.

5, 8, 12, 18, 24, 30, 36, 42, ____ a) 52 b) 46 c) 48 d) 54 e) 56

Description : 5, 8, 12, 18, 24, 30, 36, 42, ____ a) 52 b) 46 c) 48 d) 54 e) 56

Last Answer : Each term in the series is the addition of successive prime numbers. Like Prime numbers are2, 3, 5, 7, 11, 13, 17, 19, 23, 29 and so on. So first term is addition of (2 + 3). Ie 5, then second term is (3 + 5) ie ... +17)ie. 30, then (17+19)ie.36, then (19+23)ie., 42, then (23+29)i.e. 52. Answer: a)

P walks around a circular field at the rate of two rounds per hour while Q runs around it at the rate of eight rounds per hour. They start in the opposite direction from the same point at 6.45 a.m. They shall first cross each other at? a) 6.45 a.m b) 6.50 a.m c) 7.51 a.m d) 6.51 a.m e) 7.45 am

Description : P walks around a circular field at the rate of two rounds per hour while Q runs around it at the rate of eight rounds per hour. They start in the opposite direction from the same point at 6.45 a.m. They shall first cross each other at? a) 6.45 a.m b) 6.50 a.m c) 7.51 a.m d) 6.51 a.m e) 7.45 am

Last Answer : d Since P and Q move in the opposite direction along the circular field, so they will first meet each other when there is a difference of one round between the two. Relative speed of P and Q = 8+2 = 10 rounds per hour. Time ... 1/10 hr = 6 min. 6 Hrs 45 min + 6 min = 6 hrs 51 min i.e, 6.51 a.m

Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is: A.40 m B.55 m C.65 m D.50 m E.None of these

Description : Two trains of equal length are running on parallel lines in the same direction at 46 km/hr and 36 km/hr. The faster train passes the slower train in 36 seconds. The length of each train is: A.40 m B.55 m C.65 m D.50 m E.None of these

Last Answer : Answer- D (50) Explanation – Relative speed= total lengths/time (46-36) x 5/18 = [L + L ] / 36 10 x (5/18) x36 x (1/2)= L L=50 m

A train travelling at 36 kmph completely crosses another train having half its length and travelling in the opposite direction at 54 kmph, in 12 seconds. If it also passes a railway platform in 112 minutes, the length of the platform is : a) 560 metres b) 620 metres c) 700 meres d) 750 metres e) 720 meters

Description : A train travelling at 36 kmph completely crosses another train having half its length and travelling in the opposite direction at 54 kmph, in 12 seconds. If it also passes a railway platform in 112 minutes, the length ... is : a) 560 metres b) 620 metres c) 700 meres d) 750 metres e) 720 meters

Last Answer : Answer: c)

Two trains of equal lengths take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 metres, in what time (in seconds) will they cross each other travelling in opposite direction? A.12 sec B.18 sec C.14 sec D.25 sec E.None of these

Description : Two trains of equal lengths take 10 seconds and 15 seconds respectively to cross a telegraph post. If the length of each train be 120 metres, in what time (in seconds) will they cross each other travelling in opposite direction? A.12 sec B.18 sec C.14 sec D.25 sec E.None of these

Last Answer : Answer – A (12 sec) Explanation – Speed of the first train = [120 / 10] m/sec = 12 m/sec. Speed of the second train = [120 / 15] m/sec = 8 m/sec. Relative speed = (12 + 8) = m/sec = 20 m/sec. ∴ Required time = (120 + 120) / 20 secc = 12 sec

Two trains are running at 40 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 5 seconds. What is the length of the fast train? A.27 7/9 m B.28 m C.29 m D.30 2/7 m E.None of these

Description : Two trains are running at 40 km/hr and 20 km/hr respectively in the same direction. Fast train completely passes a man sitting in the slower train in 5 seconds. What is the length of the fast train? A.27 7/9 m B.28 m C.29 m D.30 2/7 m E.None of these 

Last Answer : Answer – A (27 7/9 m) Explanation – When SAME direction- MINUS Relative speed = (40-20) km/hr = [20 x 5/18] m/sec = [50/9] m/sec. Length of faster train = sxt=[50/9 x 5] m = 250/9 m = 27 7/9 m.

3 4 12 45 ? 1005 a) 152 b) 198 c) 144 d) 192 e) None of these

Description : 3 4 12 45 ? 1005 a) 152 b) 198 c) 144 d) 192 e) None of these

Last Answer : Answer: e)

Two cyclists began a training run, one starting from Moscow and the other starting from Simferopol.When the riders were 180 miles apart, a fly took an interest. Starting on one cyclists shoulder, the fly flew ahead to meet the other cyclist. After reaching him the fly then turned around and yet back. The restless fly continued to shuttleback and fourth until the pair met; then settled on the nose of one rider.The flys speed was 30 mph. Each cyclist speed was 15 mph.How many miles did the fly travel? -Riddles

Description : Two cyclists began a training run, one starting from Moscow and the other starting from Simferopol.When the riders were 180 miles apart, a fly took an interest. Starting on one cyclists shoulder, the fly flew ... was 30 mph. Each cyclist speed was 15 mph.How many miles did the fly travel? -Riddles

Last Answer : The cyclists took 6 hours to meet. The fly traveled 6*30=180 miles.

The average age of 30 boys of a class is equal to 14 years. When the age of the class teacher is included the average becomes 15 years. Find the age of the class teacher? A.50 B.44 C.45 D.42 E.None of these

Description : The average age of 30 boys of a class is equal to 14 years. When the age of the class teacher is included the average becomes 15 years. Find the age of the class teacher? A.50 B.44 C.45 D.42 E.None of these

Last Answer : Answer – C (45) Explanation – Total ages of 30 boys = 14 x 30 = 420 years Total age when class teacher is included = 15 x 31 = 465 years Age of class teacher = 465 – 420 = 45 years

Busses start from a bus terminal with a speed of 20 km/hr at intervals of 10 minutes. What is the speed of a man coming from the opposite direction towards the bus terminal if he meets the buses at intervals of 8 minutes? a) 3 km/hr b) 4 km/hr c) 5 km/hr d) 7 km/hr e) None of these

Description : Busses start from a bus terminal with a speed of 20 km/hr at intervals of 10 minutes. What is the speed of a man coming from the opposite direction towards the bus terminal if he meets the buses at intervals of 8 minutes? a) 3 km/hr b) 4 km/hr c) 5 km/hr d) 7 km/hr e) None of these

Last Answer : Distance covered in 10 minutes at 20 kmph = distance covered in 8 minutes at (20+x) kmph 20× 10/60=8/60(20+x) 200 = 160 + 8x 8x = 40 x=40/8=5 kmph Answer: c)

Three pipes P, Q and R can fill a tank from empty to full in 40 minutes, 15 minutes, and 30 minutes respectively. When the tank is empty, all the three pipes are opened. P, Q and R discharge chemical solutions X, Y and Z respectively. What is the proportion of the solution Y in the liquid in the tank after 5 minutes? a) 8 / 15 b) 7 / 15 c) 8 / 17 d) 6 / 13 e) 8 / 13

Description : Three pipes P, Q and R can fill a tank from empty to full in 40 minutes, 15 minutes, and 30 minutes respectively. When the tank is empty, all the three pipes are opened. P, Q and R discharge chemical solutions X, Y and Z respectively. ... 5 minutes? a) 8 / 15 b) 7 / 15 c) 8 / 17 d) 6 / 13 e) 8 / 13

Last Answer : a Part of the tank filled by pipe P in 1 minute = 1 / 40 Part of the tank filled by pipe Q in 1 minute = 1 / 15 Part of the tank filled by pipe R in 1 minute = 1/ 30 Here we have to find the proportion of ... together in 5 minute = 5 1/8 = 5/ 8 Required proportion = (1/3) / ( 5/8) = 8 / 15

A train overtakes two persons walking along a railway track. The first one walks at 4.5 km/hr. The other one walks at 5.4 km/hr. The train needs 8.4 and 8.5 seconds respectively to overtake them. What is the speed of the train if both the persons are walking in the same direction as the train? A.59 km/hr B.65 km/hr C.70 km/hr D.81 km/hr E. None of these

Description : A train overtakes two persons walking along a railway track. The first one walks at 4.5 km/hr. The other one walks at 5.4 km/hr. The train needs 8.4 and 8.5 seconds respectively to overtake them. What is the speed ... as the train? A.59 km/hr B.65 km/hr C.70 km/hr D.81 km/hr E. None of these

Last Answer : Answer-D (81 km/hr) Explanation4.5 km/hr =(4.5 x 5/18)m/sec =5m/4sec = 1.25 m/sec, and 5.4 km/hr =(5.4 x 5/18)m/sec =3m/2sec = 1.5 m/sec. Let the speed of the train be x m/sec. Then, (x - 1.25) ... - 12.75 => 0.1x = 2.25 => x = 22.5 Therefore Speed of the train =(22.5 x18 /5)km/hr = 81 km/hr.

A train 125 m long passes a man, running at 5 kmph in the same direction in which the train is going, in 10 seconds. The speed of the train is: A.35 km/hr B.50 km/hr C.48 km/hr D.55 km/hr E.None of these

Description : A train 125 m long passes a man, running at 5 kmph in the same direction in which the train is going, in 10 seconds. The speed of the train is: A.35 km/hr B.50 km/hr C.48 km/hr D.55 km/hr E.None of these

Last Answer : Answer – B (50 km/hr) Explanation – Let speed be S Relative speed = total lengths/time [ in this case man length is neglible compare to train so neglected] (S – 5) x 5/18 = 125 /10 S- 5 = (125/10)x(18/5) S-5 = 45 S=50 km/hr

Anjana walked at 4 kmph for a certain part of his journey and took an auto, travelling at 25 kmph for the rest of the journey. If he took 42 minutes for the entire journey, what part of the journey did he walk given that his average speed for the entire journey was 10 kmph? a) 2 km b) 1.5 km c) 3.5 km d) 4 km e) 1 km

Description : Anjana walked at 4 kmph for a certain part of his journey and took an auto, travelling at 25 kmph for the rest of the journey. If he took 42 minutes for the entire journey, what part of the journey did he walk given that his ... journey was 10 kmph? a) 2 km b) 1.5 km c) 3.5 km d) 4 km e) 1 km

Last Answer : Total time = 42 minutes = 0.7 hours. Average speed = 10 kmph Total distance = 0.7×10 = 7 km Let distance walked = W W/4 + (7-W)/25 = 0.7 Solving W = 2 Answer: a)

√1369 ×√1444 +√?=1420 a) 14 b) 196 c) 198 d) 194 e) 16

Description : √1369 ×√1444 +√?=1420 a) 14 b) 196 c) 198 d) 194 e) 16

Last Answer : √1369 ×√1444 - √? =1420 Or, √(37)2 ×√(38)2×√? = 1420 Or,37 × 38 ×√? = 1420 Or,1406 + √? =1420 Or, √? = 1420 -1406 =14 ? = 196 Answer: b)

188, 212, 236, ?, 268, 284 a) 260 b) 256 c) 252 d) 248 e) 244

Description : 188, 212, 236, ?, 268, 284 a) 260 b) 256 c) 252 d) 248 e) 244

Last Answer : The pattern is 47×4=188, 53×4=212, 59×4=236, 61×4=244, 67×4=268, 71×4=284 47, 53, 59, 61, 69 and 71 are consecutive prime numbers. Answer: e)

264 262 271 243 ? a) 302 b) 304 c) 306 d) 308 e) None of these

Description : 264 262 271 243 ? a) 302 b) 304 c) 306 d) 308 e) None of these

Last Answer : 264 – 1³ + 1 = 262 262 + 2³ + 1 = 271 271 – 3³ + 1 = 243 Answer: d)

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50'. What number is missing? -Riddles

Description : 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50'. What number is missing? -Riddles

Last Answer : 22

A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. The length of the train is :

Description : A train overtakes two persons who are walking in the same direction in which the train is going, at the rate of 2 kmph and 4 kmph and passes them completely in 9 and 10 seconds respectively. The length of the train is : a) 72 metres b) 54 metres c) 55 metres d) 45 metres e) 50 meters

Last Answer : Answer: e)

Avinash, Bala and Chandran invested Rs.45,000/-, Rs. 70, 000/- and Rs. 90,000/- respectively to start a business. At the end of two years, they earned a profit of Rs.1,64,000/-. What will be Bala’s share in the profit? a) Rs.56, 000/- b) Rs.46, 000/- c) Rs. 50, 000/- d) Rs.75, 000/- e) None of these

Description : Avinash, Bala and Chandran invested Rs.45,000/-, Rs. 70, 000/- and Rs. 90,000/- respectively to start a business. At the end of two years, they earned a profit of Rs.1,64,000/-. What will be Bala’s share in the profit? a) Rs.56, 000/- b) Rs.46, 000/- c) Rs. 50, 000/- d) Rs.75, 000/- e) None of these

Last Answer : Profit sharing ratio of Avinash,Bala & Chandran = 45000 : 70000 : 90,000 = 45 : 70 : 90 = 9 : 14 : 18 Bala's share of profit after two year =Rs.164000 × 14 × 41 = Rs. 4000 ×14 = Rs. 56000 Answer: a)

Two trains are running in opposite directions with the same speed. If the length of each train is 120 metres and they cross each other in 12 seconds, then the speed of each train (in km/hr) is: A.12 kmph B.24 kmph C.36 kmph D.48 kmph E.None of these

Description : Two trains are running in opposite directions with the same speed. If the length of each train is 120 metres and they cross each other in 12 seconds, then the speed of each train (in km/hr) is: A.12 kmph B.24 kmph C.36 kmph D.48 kmph E.None of these

Last Answer : Answer – C (36 kmph) Explanation – Let the speed of each train be x m/sec. Then, relative speed of the two trains = 2x m/sec. So, 2x = (120 + 120)/12 ⇔ 2x = 20 ⇔ x = 10. ∴ Speed of each train = 10 m/sec = [10 x 18/5] km/hr = 36 km/hr

A father runs after his son, who is 1000 meters ahead. The father runs at a speed of 1 kilometre every 8 minutes, and the son runs at a speed of 1 kilometer every 12 minutes. How much distance has the son covered at the point when the father overtakes him? a) 2500 meters b) 2000 meters c) 1500 meters d) 1000 meters e) 1200 meters

Description : A father runs after his son, who is 1000 meters ahead. The father runs at a speed of 1 kilometre every 8 minutes, and the son runs at a speed of 1 kilometer every 12 minutes. How much distance has ... father overtakes him? a) 2500 meters b) 2000 meters c) 1500 meters d) 1000 meters e) 1200 meters

Last Answer : Time taken is same for both father and son Let x be the distance son travelled before being overtaken by his father Time taken by son = x/5 km/hour Time taken by father = (1000 + x) / 7.5 km/hr Since, time taken is same x/5 = (1000 + x) / 7.5 or x = 2000m Answer: b)

Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour? A.10 min B.12 min C.18 min D.15 min E.None of these

Description : Excluding stoppages, the speed of a bus is 54 kmph and including stoppages, it is 45 kmph. For how many minutes does the bus stop per hour? A.10 min B.12 min C.18 min D.15 min E.None of these

Last Answer : Answer – A (10 min) Explanation – Due to stoppages, it covers 9 km less.Time taken to cover 9 km = (9/54 x 60) min = 10 min

A man rows 750m in 775 seconds against the stream and returns in 7 1/2 minutes. What is rowing speed in still water ? A.4.7km/hr B. 4km/hr C.3.5km/hr D.6km/hr

Description : A man rows 750m in 775 seconds against the stream and returns in 7 1/2 minutes. What is rowing speed in still water ? A.4.7km/hr B. 4km/hr C.3.5km/hr D.6km/hr

Last Answer : Answer-A Basic Formula: i) Speed in still water = ½ (a+b) kmph where a' is speed downstream and b' is speed upstream ii) a km / hr = a x 5/18 m /s iii) a m/sec = a x 18/5 km/hr Explanation: Speed upstream b' ... (750/450 + 750/675 ) x 18/5 km/hr = ½ (5/3 + 30/31) x 18/5 km/hr = 4.7 km/hr

In a class there are 15 boys and 10 girls. Three students are selected at random. The difference between the probability that 2 boys and 1 girl are selected compared to 1 boy and 2 girls are selected is: a) 23/78 b) 19/88 c) 15/92 d) 4/23 e) 7/46

Description : In a class there are 15 boys and 10 girls. Three students are selected at random. The difference between the probability that 2 boys and 1 girl are selected compared to 1 boy and 2 girls are selected is: a) 23/78 b) 19/88 c) 15/92 d) 4/23 e) 7/46

Last Answer : 2 boys, 1 gi(Prl = (15c2×10c1) / 25c3 = 1050/2300 1 boy, 2 girls = (15c1×10c2) / 25c3 = 675/2300 Difference = (1050 - 675)/2300 = 375/2300 = 15/92 Answer: c)

A 270 m long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train? A.180 B.230 C.245 D.235 E.None of these

Description : A 270 m long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train? A.180 B.230 C.245 D.235 E.None of these

Last Answer : Answer – B (230) Explanation – Relative speed = total lenghths /time [120 +80] x5/18 ={ 270 + other train length (say L) } / 9 sec (x5/18 to convert km/hr to m/sec ) 200 x (5/18) x9 = 270 + L 500 = 270 +L L=230 m Note: always do cutting ,avoid solving exact

The sum of ages of Sunil and his father is 46 years. 3 years back, father’s age was 4 times sunil’s age. find present age of Sunil. a) 7 years b) 8 years c) 11 years d) 12 years e) None of these

Description : The sum of ages of Sunil and his father is 46 years. 3 years back, father’s age was 4 times sunil’s age. find present age of Sunil. a) 7 years b) 8 years c) 11 years d) 12 years e) None of these

Last Answer : Sum of their ages, 3 years ago = 46 – (2 × 3) = 40 years sunil’s age, 3 years ago = 1/5 × 40 = 8 years sunil’s present age = 8 + 3 = 11 years Answer: c)

The title of the problem tells you how to approach these four questions.(A). A bus leaves Moscow for Tula at noon. An hour later a cyclist leaves Tula for mosco, moving slower than the bus. When the bus and cyclist meet, which one of the two will be farther from Moscow?(B). Which is worth more: a pound of $10 gold peices or half a pound of $20 gold pieces?(C). At six o'clock the wall clock struck 6 times. Checking with my watch, I noticed the time between the first and last strokes was 30 seconds. How long will the clock take to strike 12 at midnight?(D). Three swallows fly outward from a point. When will they all be on the same plane in space?Now check the answers. Did you fall into any of the traps which lurk in these simple problems? -Riddles

Description : The title of the problem tells you how to approach these four questions.(A). A bus leaves Moscow for Tula at noon. An hour later a cyclist leaves Tula for mosco, moving slower than the bus. ... Now check the answers. Did you fall into any of the traps which lurk in these simple problems? -Riddles

Last Answer : (A). Neither (B). A pound of metal is always more than half a pound of the same metal. (C). Six strokes took 30 seconds, therefore 12 strokes will take 60 seconds. But when the clock struck ... , therefore 12 strokes will take 66 seconds. (D). There is always a plane that contains any 3 points

A thief is noticed by a policeman from a distance of 200 m. The thief starts running and the policeman chases him. The thief and the policeman run at the rate of 10 km and 11 km per hour respectively. What is the distance between them after 6 minutes? A.100 m B.150 m C.190 m D.200 m E.None of these

Description : A thief is noticed by a policeman from a distance of 200 m. The thief starts running and the policeman chases him. The thief and the policeman run at the rate of 10 km and 11 km per hour respectively. What is the distance between them after 6 minutes? A.100 m B.150 m C.190 m D.200 m E.None of these

Last Answer : Answer- A(100m) Explanation: Relative speed of the thief and policeman = (11 – 10) km/hr = 1 km/hr Distance covered in 6 minutes =[(1/60)*6] km = (1/10)km = 100 m. Distance between the thief and policeman = (200 – 100) m = 100 m.

Two, trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is: A. 1: 2 B. 4 : 3 C. 7 : 8 D. 3 : 4 E. none of these

Description : Two, trains, one from Howrah to Patna and the other from Patna to Howrah, start simultaneously. After they meet, the trains reach their destinations after 9 hours and 16 hours respectively. The ratio of their speeds is: A. 1: 2 B. 4 : 3 C. 7 : 8 D. 3 : 4 E. none of these

Last Answer : Answer- B (4:3) Explanation: Let us name the trains as A and B. Then, trick formula (A’s speed) : (B’s speed) = square root of b : square-root of a =square-root of 16 : square-root of 9 = 4 : 3.

The average age of two persons is 46 years. 16 years back the ratio between their ages were 1 : 2, then what is the difference between present ages of these two persons? 1) 16 years 2) 20 years 3) 24 years 4) 12 years 5) 8 years

Description : The average age of two persons is 46 years. 16 years back the ratio between their ages were 1 : 2, then what is the difference between present ages of these two persons? 1) 16 years 2) 20 years 3) 24 years 4) 12 years 5) 8 years

Last Answer : 2) 20 years

Speed of a boat in standing water is 9kmph and the speed of the stream is 1.5kmph. A man rows to a place at a distance of 10.5 km and comes back to the starting point. Find the total time taken by him. A.24 hours B.16 hours C.20 hours D.15 hours

Description : Speed of a boat in standing water is 9kmph and the speed of the stream is 1.5kmph. A man rows to a place at a distance of 10.5 km and comes back to the starting point. Find the total time taken by him. A.24 hours B.16 hours C.20 hours D.15 hours

Last Answer : Answer- A Basic Formula: i. speed = distance traveled / time taken ii. speed of the stream = ½ (a-b) km/hr iii. speed in still water = ½ (a+b) km/hr Explanation: Speed in still water= ½ (a+b) = 9km ... gives a = 10.5km/hr ; b=7.5 kmphr Total time taken by him = 105/10.5 + 105/7.5 = 24 hours

The distance between two cities A and B is 330km. A train starts from A at 8 (a)m. and travels towards B at 60 km/hr. Another train starts from B at 9 (a)m. and travels towards A at 75 km/hr. At what time do they meet? a) 10 am. b) 10 : 30 am. c) 11 am. d) 11 : 30 am. e) None of these

Description : The distance between two cities A and B is 330km. A train starts from A at 8 (a)m. and travels towards B at 60 km/hr. Another train starts from B at 9 (a)m. and travels towards A at 75 km/hr. At what time do they meet? a) 10 am. b) 10 : 30 am. c) 11 am. d) 11 : 30 am. e) None of these

Last Answer : Distance travelled by first train in one hour = 60 x 1 = 60 km Therefore, distance between two train at 9 a.m. = 330 – 60 = 270 km Now, Relative speed of two trains = 60 + 75 = 135 km/hr Time of meeting of two trains =270/135=2 hrs. Therefore, both the trains will meet at 9 + 2 = 11 A.M. Answer: c)

Two stations X and Y are 170 km apart on a straight line. One train starts from X at 6 a.m. and travels towards Y at 25 kmph. Another train starts from Y at 8 a.m. and travels towards X at a speed of 35 kmph. At what time will they meet? a) 11. 30 a.m b) 10.30 a.m c) 11 a.m d) 9 a.m e) 10 am

Description : Two stations X and Y are 170 km apart on a straight line. One train starts from X at 6 a.m. and travels towards Y at 25 kmph. Another train starts from Y at 8 a.m. and travels towards X at a speed of 35 kmph. At what time will they meet? a) 11. 30 a.m b) 10.30 a.m c) 11 a.m d) 9 a.m e) 10 am

Last Answer : e Suppose they meet z hours after 6 a.m. Distance covered by X in z hours = 25× z km. Distance covered by Y in (z - 2) hours = 35(z - 2) km. Therefore 25z + 35(z- 2) = 170 60z = 240 x = 4. So, they meet at 10 a.m.