Description : If three cubes of copper, each with an edge 6 cm, 8 cm and 10 cm respectively are melted to form a single cube, -Maths 9th
Last Answer : 20.8 cm Let the edge of the single cube be ‘a’ cm. Then, total volume melted = Volume of cube formed ⇒ (6)3 + (8)3 + (10)3 = a3 ⇒ a3 = 216 + 512 + 1000 = 1728 ... Diagonal of the new cube = 3–√a=(3–√×12)3a=(3×12) cm = 20.8 cm (approx.)
Description : One alloy contains silver and copper in the ratio 5:1 and the other contains in the ratio 7:2 respectively. What weights of the 2 must be melted together, so as to make a 5 lb mass with 80% silver? A)5:3 B)3:2 C)2:3 D)2:5
Last Answer : B)3:2
Description : A cuboid shaped wooden block has 6 cm length, 4 cm breadth and 1 cm height. 2. Two faces measuring 4 cm x 1 cm are coloured in black. 3. Two faces measuring 6 cm x 1 cm are coloured in red. 4. Two faces ... and black colours on at least one side of the cube will be formed? (a)16 (b)12 (c)10 (d)4
Last Answer : Answer key : (d)
Description : A 4 cm cube is cut into 1 cm cubes. Calculate the total surface area of all the small cubes. -Maths 9th
Last Answer : Side of cube = 4 cm But cutting into 1 cm cubes, we get = 4 x 4 x 4 = 64 Now surface area of one cube = 6 x (1)² = 6 x 1=6 cm² and surface area of 64 cubes = 6 x 64 cm² = 384 cm²
Description : How many small cubes each of 96 cm^2 surface area can be formed from the material obtained by melting a larger cube of 384 cm^2 surface area ? -Maths 9th
Last Answer : answer:
Description : How many 20 centimeter cubes to make a cube with edges that are 3 cm long?
Last Answer : You need 0.003375 of one cube.
Description : The side of a quadrilateral ABCD are 6cm,12cm,8cm,12cm,4cm (taken in oder) respectively and the angle between the 1st two side is a right angle. Find area of tiresome by herons fourmula -Maths 9th
Last Answer : Given ABCD is a quadrilateral having sides AB=6cm, BC=8cm, CD=12cm and DA=14 cm. Now. Join AC. We have, ABC is a right angled triangle at B. Now, AC2 =AB2 +BC2 [by Pythagoras theorem] Now, AC2=AB2 ... 1+6-√)cm2 =24+246=24(1+6)cm2 Hence, the area of quadrilateral is 241+6-√−−−−−−√cm2 241+6cm2 .
Last Answer : This answer was deleted by our moderators...
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
Description : A cube of side 4cm is painted with 3 colors red, blue and green in such a way that opposite sides are painted in the same color. This cube is now cut into 64 cubes of equal size. ➢ How many ... one side painted. ➢ How many cubes have no side painted. ➢ How many have exactly one side not painted.
Last Answer : Here are the answers. Cubes that have at least two sides painted in different colours are 24 + 8 = 32. Cubes that have only one side painted are 24. Cubes that have no side painted = 8. Cubes that have exactly one side not painted = 0.
Description : A cube of side 4cm is painted with 3 colors red, blue and green in such a way that opposite sides are painted in the same color. This cube is now cut into 64 cubes of equal size. 1. How many ... side painted. 3. How many cubes have no side painted. 4. How many have exactly one side not painted.
Last Answer : Here are the answers. 1. Cubes that have at least two sides painted in different colours are 24 + 8 = 32. 2. Cubes that have only one side painted are 24. 3. Cubes that have no side painted = 8. 4. Cubes that have exactly one side not painted = 0.
Description : Each Student of a class collected some money for the trip. The total money collected by each student was equal to the cube of the total number of students. If the total amount collected was Rs. 29791. find the total number of students. 1. 31 2. 30 3. 28 4. 37 5. 39
Last Answer : 1; Total number of students
Description : Present ages of Simmi and Anu are in the ratio of 5 : 4 respectively. Three years hence, the ratio of their ages will become 11 : 9 respectively, What is Anu’s present age in years? A.20 B.24 C.28 D.35 E.None of these
Last Answer : Answer – B (24) Explanation – Let the present ages of Simmi and Anu be 5x years and 4x years respectively Then, [5X + 3] / [4X + 3] =11/9 x=6 Anu’s present age = 4X = 24 years
Description : The shares of A, B and C are in the ratio 4 : 5 : 8. If each of the shares is increased by 75%, 20% and 25% respectively, what will be the ratio of their new shares? 1 : 5 : 3 : 5 2 : 7 : 6 : 9 3 : 7 : 6 : 10 4 : 5 : 6 : 10 5 : None of these
Last Answer : 3 : 7 : 6 : 10
Description : Ages of DEEPA and Subha are presently in the ratio of 5 : 6 respectively. Six years hence this ratio will become 6 : 7 respectively. What was Subha’s age 5 years ago? a) 33 years b) 32 years c) 35 years d) 31 years e) None of these
Last Answer : Present ratio of Deepa&Subha = 5 : 6 Six year hence ratio of Deepa&Subha = 6 : 7 Difference between ratio = 1 Difference in ages between present & future = 6 year. 1 ratio=6 yrs & SUBHA's age = 6 6 =36 year 5 year ago ... = 7 6 = 42 year B's age 5 year ago = 42-6-5 = 42-11 = 31 year Answer: d)
Description : Mr. Xavier invested a certain amount in Debit and Equity funds in the ratio of 4 : 5 respectively. At the end of one year, he earned a total dividend of 30% on his investment. After one year he reinvested the amount including ... . 81,000/- (c) Rs. 60,000/- (d) Rs. 65,000/- (e) None of these
Last Answer : (a) Rs. 75,000/-
Description : A cuboid shaped wooden block has 6 cm length, 4 cm breadth and 1 cm height. 17. Two faces measuring 4 cm x 1 cm are coloured in black. 18. Two faces measuring 6 cm x 1 cm are coloured in red. 19. Two faces ... colour on two sides and rest of the four sides having no colour ? (a)12 (b)10 (c)8 (d)4
Last Answer : Answer key : (c)
Description : A cuboid shaped wooden block has 6 cm length, 4 cm breadth and 1 cm height. 12. Two faces measuring 4 cm x 1 cm are coloured in black. 13. Two faces measuring 6 cm x 1 cm are coloured in red. 14. Two ... How many cubes will have 4 coloured sides and two non-coloured sides ? (a)8 (b)4 (c)16 (d)10
Last Answer : Answer key : (b)
Description : A cuboid shaped wooden block has 6 cm length, 4 cm breadth and 1 cm height. 7. Two faces measuring 4 cm x 1 cm are coloured in black. 8. Two faces measuring 6 cm x 1 cm are coloured in red. 9. Two faces measuring ... 1 cm(from 4 cm side). How many small cubes will be formed? (a)6 (b)12 (c)16 (d)24
Description : Two pipes fills a tank in 12 hours and 15 hours respectively while a third pipe empties the tank in 18 hours. !f all three pipes operate simultaneously, in what time will the tank be full? a) 10 hours b) 10 10/17 hours c) 11 hours d) 9 hours e) 12 1/17 hours
Last Answer : b) 10 10/17 hours
Description : A,B and C can do piece of work in 11 days,20 days and 55 days respectively, working alone. How soon can the work be done if a is assisted by B and C on alternate days/ a) 6 b) 7 c) 8 d) 9 e) 10
Last Answer : Work done by A and B in one day = 1/11 + 1/20 =31/220 Work done by A and C in one day = 1/11 + 1/55 =6/55 Work done in 2 days = 31 /220+6/55=55/220 = ¼ Hence, 1/4 of the work is done in 2 days Hence, it takes 8 days to finish the work Answer : c
Description : A sum of money is divided among Suresh, Ganesh, Vignesh and Mahesh in the ratio of 3 : 4 : 9 : 10 respectively. If the share of Vignesh is Rs.2,580/-more than the share of Ganesh, then what is the total amount of money of Suresh ... ,985/- b) Rs. 6,487/- c) Rs. 6,708/- d) Rs. 7,156/- e) Rs. 8,457/-
Last Answer : According to the question, difference of ratio of Ganesh and Vignesh is 5 so, 1 ratio = 2580/5 = 516 Now, total ratio of Suresh + Mahesh = 13 So, total money = 13 × 516 = Rs. 6708 Answer: c)
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
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.
Description : Find the magnetic field intensity at the radius of 6cm of a coaxial cable with inner and outer radii are 1.5cm and 4cm respectively. The current flowing is 2A. a) 2.73 b) 3.5 c) 0 d) 1.25
Last Answer : c) 0
Description : When two ice cubes are pressed together, they join to form one cube. Which one of the following helps to hold them together? (1) Hydrogen bond formation (2) Vander waals forces (3) Covalent attraction (4) Dipole interaction
Last Answer : (1) Hydrogen bond formation Explanation: When two ice cubes are pressed together, they join to form one cube due to hydrogen bond.
Last Answer : Hydrogen bond formation
Description : In parallelogram PQRS, PQ = 10cm. The altitudes corresponding to the sides PQ and SP are respectively 6cm and 8cm. Find SP. -Maths 9th
Last Answer : Solution :-
Description : Two equal sums are lent at the same time at 6% and 5 % simple interest respectively. The former is recovered 24 months earlier than the latter. And the amount in each case is Rs. 2400. Find the sum of money lent initially. a) 1500 b) 2000 c) 2400 d) 3000 e) 3600
Last Answer : Let the sum be S, time be ‘n’ years for 6%. n+2 years for 5% 2400 = S + S ×n × 6/100 2400 = S + S × (n+2) × 5/100 So, 6n = 5(n+2) or n = 10 years. 2400 = S + S × 10 × 6/100 = 1.6S S = 2400/1.6 = 1500 Answer: a)
Description : A and B working alone can finish a job in 5 days and 7 days respectively. They work at it alternately for a day. If A starts the work, find in how many days the job will be finished? a) 29/5 b) 11/5 c) 24/5 d) 21/5 e) None of these
Last Answer : Work done by A in one day = 1/5 and work done by B in one day = 1/7 They are working alternately. Therefore, Work done in first two day = (1/5 + 1/7) = 12/35 Work done in first four day = 24/35 Work done in ... = 4/35/1/7 = 4/5 of the day. Therefore Total days taken = 5 + 4/5 = 29/5 days Answer: b)
Description : A and B are 3 years and 2 years old respectively. Their father is 40 years. After how many years, father’s age would be twice of combined age of A and B? a) 5 years b) 10 years c) 15 years d) 20 years e) None of these
Last Answer : Father’s age = 40 years. Children’s combined age = 3 + 2= 5 years Double of their ages = 2 × 5 = 10 years Difference between father’s age and combined age = 40 – 10 = 30 years required time = 1/ (2 + 1) × 30 = 10 years Answer: b)
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.
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.
Description : Two cubes of side 2 cm each are joined end to end. Find the volume of the cuboid so formed. -Maths 9th
Last Answer : When two cubes of side 2 cm each are joined end to end then, Length (l) = (2 + 2) = 4cm Breadth (b) = 2 cm; Height (h) = 2 cm ∴ Volume of cuboid = lbh = 4 x 2 x 2 = 16 cm3
Description : How many cubes with side links of 1/4 cm does it take to fill the prism?
Last Answer : 0.25
Description : Present ages of A and B are 50 years and 18 years respectively. In how many years will A be twice as old as B? a) 14 years b) 15 years c) 16 years d) 18 years e) None of these
Last Answer : Let the required time be x years. then (50+x) = 2 (18 + x) = 50 + x = 36 + 2x x = 14 years. Alternative method : Double of B’s age = 2 × 18 = 36 years difference between A’s present age and double of B’s age = 50 – 36= 14 years. A will be twice of B’s age after 14 years. Answer: a)
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)
Description : Kathir and Anand can do a work in 20 days and 30 days respectively. Kathir started the work and left after 4 days. Anand took over and completed the work. In how many days was the total work completed? a) 28 days b) 20 days c) 23 days d) 25 days e) 26 days
Last Answer : a Kathir’s one day’s work= 1/20 Kathir’s 4 day’s work =4* (1/20) = 1/5 Work left= 1-1/5 = 4 /5 Anand’s one day’s work= 1/30 Anand can do work in = (4/5) *(30/ 1) = 24 days So total days = 24+4 = 28 days
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
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.
Description : Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is: A.1 : 3 B.3 : 4 C.3 : 2 D.Data inadequate E.None of these
Last Answer : Answer - C (3 : 2) Explanation - Let the speeds of the two trains be x m/sec and y m/sec respectively. Then, length of the first train = 27x metres, and length of the second train = 17y metres. relative speed = total ... 23x + 23y = 27x + 17 y 27x-23x= 23 y-17y 4x=6y x/y=6/4=3/2= 3:2
Description : Two trains are moving in opposite directions at 60 km/hr and 90 km/hr. Their lengths are 1.10 km and 0.9 km respectively. The time taken by the slower train to cross the faster train in seconds is: A.58 sec B.50 sec C.48 sec D.56 sec E.None of these
Last Answer : Answer – C (48 sec) Explanation – Relative speed = all lengths/time [60+90] = [1.10 +0.9 ]/time [ PLUS when opposite direction] time=2/150 = 1/75 h 1 hour______3600 sec 1/75 hr______? ?= 3600/75=48 sec
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.
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
Description : Are there ice cube trays that make thin or partially frozen ice cubes?
Last Answer : answer:Ding ding ding ding ding. You've just won Jeruba's Weird Question of the Day lottery. Congratulations! I don't think there is anything that would yield partially frozen ice cubes other than ... of a green plastic fruit basket from the produce section, to help the thin sheet hold its shape.
Description : There are two identical cubes. Out of one cube, a sphere of maximum volume (VS) is cut off. Out of the second cube, a cone of maximum volume -Maths 9th
Description : Find the smallest number which must be subtracted from the following to make them perfect cubes .What are the corresponding cube roots?
Last Answer : Find the smallest number which must be subtracted from the following to make them perfect cubes .What are the ... A. 350 B. 833 C. 1400 D. 1730
Description : Four solid cubes of different metals, each one having a mass of one kg are weighed in water select the correct statement: (a) all cubes weigh equal (b) cube with minimum density weighs minimum (c) cube with minimum density weighs maximum (d) the mass of all cubes will be the same
Last Answer : Ans:(b)