Description : A box contains 3red, 8 blue and 5 green marker pens. If 2 marker pens are drawn at random from the pack, not replaced and then another pen is drawn. What is the probability of drawing 2 blue marker pens and 1 red marker pen? a) 3/20 b) 1/20 c) 7/20 d) 9/20
Last Answer : Answer: B) Probability of drawing 1 blue marker pen =8/16 Probability of drawing another blue marker pen = 7/15 Probability of drawing 1 red marker pen = 3/14 Probability of drawing 2 blue marker pens and 1 red marker pen = 8/16*7/15*3/14=1/20
Description : Consider a pack contains 2black, 9 white and 3 pink pencils. If a pencil is drawn at random from the pack, replaced and the process repeated 2 more times, What is the probability of drawing 2 black pencils and 1 pink pencil? a)3/ 49 b)3/686 c)3/14 d)3/545
Last Answer : Answer: B) Here, total number of pencils = 14 Probability of drawing 1 black pencil = 2/14 Probability of drawing another black pencil = 2/14 Probability of drawing 1 pink pencil = 3/14 Probability of drawing 2 black pencils and 1 pink pencil = 2/14 * 2/14 * 3/14 = 3/686
Description : Two cards are drawn at random from a pack of 52 cards. What is the probability that both of them are either black or queen cards? a) 55/442 b) 54/221 c) 55/221 d) 51/221
Last Answer : c) 55/221
Description : What is the probability that a two digit number selected at random will be a multiple of '3' and not a multiple of '7'? e) 13/45 f) 14/45 g) 23/90 h) 19/45
Last Answer : Answer: a
Description : All red face cards are removed from a pack of playing cards. The remaining cards are well shuffled and then a card is drawn at random from them. Find the probability that the drawn card is face card. a. 2/23 b. 7/44 c. 3/23 d. 4/25
Last Answer : c. 3/23
Description : The probability that an egg does not hatch is 1/3. What is the probability that 3 out of 4 eggs hatch? a) 8/81 b) 23/81 c) 32/81 d) 8/9
Last Answer : c) 32/81
Description : There are 6 positive numbers and 8 negative numbers. Four numbers are chosen at random and multiplied. The probability that the product is a positive number is: a) 502/1001 b) 505/1001 c) 501/1001 d) 503/1001
Last Answer : b) 505/1001
Description : A bag contains 7 red and 5 green balls. The probability of drawing all four balls asred balls, when four balls are drawn at random is -Maths 9th
Last Answer : (b) \(rac{7}{99}\)There are (7 + 5) = 12 balls in the bag. 4 balls can be drawn at random from 12 balls in 12C4 ways. ∴ n(S) = 12C4 = \(rac{|\underline{7}}{|\underline3|\underline4}\) = \(rac{7 imes6 imes5}{3 ... ) = 35∴ Required probability = \(rac{n(A)}{n(S)}\) = \(rac{35}{495}\) = \(rac{7}{99}\).
Description : I bought 15 pens and sold 12 of them at the cost price of 18 pens. What is the profit percentage? a) 50 b) 25 c) 30 d) 45
Last Answer : a) 50
Description : A Package contains 12 pack of variety1 drink, 6 pack of variety2 drink and 8pack of variety3 drink. Three packsof them are drawn at random, what is the probability that the three are not of the same variety? a) 37/325 b) 288/325 c) 188/325 d) None of these
Last Answer : Answer: B) Total number of drink pack= 12+6+8= 26. Let S be the sample space. Then, n(S) = number of ways of taking 3 drink pack out of 26. Therefore, n(S) = 26C3 = 2600 Let Ebe the ... 296/2600=37/325 Then, the probability of taking 3 pack are not of the same variety = 1 - 37/325= 288/325
Description : How many numbers greater than 400 can be formed with digits 3,4,8,9 with no digits being repeated? a) 24 b) 18 c) 42 d) 45
Last Answer : c) 42
Description : A box contains 2 black, 3 orange and 4 pink ribbons. If two ribbons are drawn at random. What is the probability that both are orange? 1) 5/12 2) 1/13 3) 1/14 4) 1/12 5) 1/24
Last Answer : 4) 1/12
Description : Find the number of divisors of 2475 that are not perfect squares? a) 14 b) 16 c) 20 d) 10
Last Answer : a) 14
Description : A card is drawn at random from a well-shuffled pack of 52 cards. Find the probability of getting a red card or a diamond or a jack ? -Maths 9th
Last Answer : (d) \(rac{7}{13}\)Here n(S) = 52 Let A, B, C be the events of getting a red card, a diamond and a jack respectively. ∵ There are 26 red cards, 13 diamonds and 4 jacks, n(A) = 26, n(B) = 13, n(C) = 4 ⇒ n(A ∩ B) = ... rac{1}{52}\)= \(rac{44}{52}\) + \(rac{16}{52}\) = \(rac{28}{52}\) = \(rac{7}{13}\) .
Description : Two cards are drawn at random from a pack of 52 cards.what is the probability that either both are Red or both are king? A) 52/221 B) 55/190 C) 55/221 D) 19/221
Last Answer : Answer: C) We have n(s) = 52C2 = 1326. Let A = event of getting both red cards B = event of getting both king A∩B = event of getting king of red cards n(A) = 26C2 = 325, n(B)= 4C2= 6 and n(A∩B) = 2C2 = 1 P(A ... S) = 1/1326 P(A∪B) = P(A) + P(B) - P(A∩B) = (325+6-1) / 1326 = 330/1326 = 55/221
Description : Two cards are drawn at random from a well-shuffled pack of 52 cards. What is the probability that either both are black or both are kings ? -Maths 9th
Last Answer : (b) \(rac{55}{221}\)S : Drawing 2 cards out of 52 cards ⇒ n(S) = 52C2 = \(rac{|\underline{52}}{|\underline{52}|\underline2}\) = \(rac{52 imes51}{2}\) = 1326A : Event of drawing 2 black cards out of 26 black cards⇒ n ... ) + \(rac{6}{1326}\) - \(rac{1}{1326}\) = \(rac{330}{1326}\) = \(rac{55}{221}\).
Description : When two dice are rolled, find the probability of getting a greater number on the first die than the one on the second, given that the sum should equal 8. a) 5/18 b) 1/18 c) 2/5 d) 1/5
Last Answer : c) 2/5
Description : An anti-air craft gun can take a maximum of four shots at an enemy plane moving away from it. The probability of hitting the plane at the first, second, third and fourth shots are 0.4, 0.3, 0.2 and 0.1 ... is hit when all the four shots are fired? a) 0.6872 b) 0.4379 c) 0.6976 d) 0.3452
Last Answer : c) 0.6976
Description : A man can hit a target once in 4shots. If he fires 4 shots in succession, what is the probability that he will hit his target? a) 175/256 b) 81/256 c) 1/256 d) 1/256
Last Answer : a) 175/256
Description : A container contains 55 litres of milk. From this container 5.5 litres of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container? a) 32 b) 29.16 c) 43 d) 27.12 e) 40.09
Last Answer : E Where x is the initial quantity of milk in the cask y is the quantity of milk withdrawn in each process and n is the number of processes. Initial quantity:55 Withdrawn quantity=5.5 number of times repeated ... of milk left after the 3rd operation =55*((55-5.5)/55) ^3 =40.09litres.
Description : The external length, breadth and height of a closed box are 10cm, 9cm and 7cm respectively. The total inner surface area of the box is 262 sq.cm. If the walls of the box are of uniform thickness “t” cm, then “t” equals a) 1cm b) 23/3 cm c) 28/9 cm d) 42.5 cm
Last Answer : a) 1cm
Description : A carton contains 12 green and 8 blue bulbs .2 bulbs are drawn at random. Find the probability that they are of same colour. A) 91/47 B) 47/105 C) 47/95 D) 95/47
Last Answer : Answer: C) Let S be the sample space Then n(S) = no of ways of drawing 2 bulbs out of (12+8) = 20c2=20*19/2*1=190 Let E = event of getting both bulbs of same colour Then, n(E) = no of ways (2 bulbs out of 12) ... 12C2+ 8C2=(132/2)+(56/2) = 66+28 = 94 Therefore, P(E) = n(E)/n(S) = 94/190 = 47/95
Description : A basket contains 2 blue, 4 red, 3 green and 5 black balls. If 4 balls are picked at random, what is the probability that -Maths 9th
Last Answer : (d) None of theseThe month having 3 days less than 31 days has 28 days, i.e, it is the month of February. P(Choosing February) = \(rac{1}{12}\).
Description : What is the probability a well shuffled pack of 52 cards a card is drawn at random find the probability that it is either a heart or a queen?
Last Answer : 41365
Description : Three cards are drawn at random from an ordinary pack of cards. Find out the probability that they will consist of a king, aqueen and an ace?
Last Answer : Answer: 64/2210.
Description : A bag contains 5 green and 7 red balls, out of which two balls are drawn at random. What is the probability that they are of the same colour ? -Maths 9th
Last Answer : (d) \(rac{31}{66}\)Total number of balls in the bag = 12 (5 Green + 7 Red) Let S be the sample space of drawing 2 balls out of 12 balls.Thenn(S) = 12C2 = \(rac{12 imes11}{2}\) = 66∴ Let A : Event of drawing two red balls⇒ ... \(rac{n(B)}{n(S)}\) = \(rac{21}{66}\) + \(rac{10}{66}\) = \(rac{31}{66}\).
Description : Which of the following represents the largest 4-digit number which can be added to 7249 in order to make the derived number divisible by each of 12,14,21,33 and 54? a) 9123 b) 9383 c) 8727 d) 8673
Last Answer : b) 9383
Description : A Receptacle contains 3violet, 4purple and 5 black balls. Three balls are drawn at random from the receptacle. The probability that all of them are purple, is: A)3/55 B)7/55 C)1/55 D)9/55
Last Answer : Answer: C) Let S be the sample space. Then, n(S) = number of ways of drawing 3 balls out of 12 = 12C3 = 220 Let E = event of getting all the 3 purple balls. n(E) = 4C3= 4 P(E) = n(E)/n(S) = 4/220 = 1/55
Description : A computer program selects an integer in the set {k : 1 ≤ k ≤ 10,00,000} at random and prints out the result. This process is repeated 1 million times. What is the probability that the value k = 1 appears in the printout atleast once ? (A) 0.5 (B) 0.704 (C) 0.632121 (D) 0.68
Last Answer : (C) 0.632121
Description : If a clock strikes once at 1’o clock, twice at 2’o clock and twelve times at 12’o clock and again once at 1’o clock and so on, how many times will the clock strike in the course of 2 days? a) 156 b) 312 c) 78 d) 288
Last Answer : b) 312
Description : A vessel contains 100 litres of milk. From this, 10 litres of milk was taken out and replaced by water. The process was repeated further two times. How much milk is now contained by the vessel? a) 72.9 litres b) 60.4 litres c) 71.6 litres d) 81 litres e) None of these
Last Answer : Milk after three replacement =100 × (90/100)3 = 72.9 litres Answer: a)
Description : Two cards are drawn from a pack of 52 cards. What is the probability that either both are red or both are kings ? -Maths 9th
Last Answer : Let S : Drawing 2 cards out of 52 card A : Drawing 2 red cards B : Drawing 2 kings A ∪ B : Drawing 2 red cards or 2 kings ∴ n(S) = 52C2 n(A) = 26C2 (∵ There are 26 red cards) n(B) = 4C2 ... \(rac{4 imes3}{52 imes51}\) - \(rac{2}{52 imes51}\) = \(rac{660}{2652}\) = \(rac{55}{221}.\)
Description : There are 2 vessels. 1st vessel contains 5white and 5 blue thread roll. 2nd vessel contains 4 white and 6 black thread roll. One roll is taken at random from first vessel and put to second vessel without noticing its color ... second roll being a white colored roll? A) 11/13 B) 9/11 C) 13/11 D) 5/12
Last Answer : Answer: B) Case 1: first was a white roll Now it is put in second vessel, so total white rolls in second vessel = 4+1 = 5, and total rolls in second vessel = 10+1 = 11 So probability of white roll ... = 5/11+4/11 = 9/11 (added the cases because we want one of these cases to happen and not both)
Description : Find the probability that the three cards drawn from a pack of 52 cards are all black ? -Maths 9th
Last Answer : Number of ways in which three cards can be drawn from a pack of 52 cards n(S) = 52C3. Let A : Event of drawing all the three cards as black Then, n(A) = 26C3 (∵There are 26 black cards)∴ P(A ... (rac{^{26}C_3}{^{52}C_3}\) = \(rac{26 imes25 imes24}{52 imes51 imes50}\) = \(rac{2}{17}.\)
Description : A bag contains 5 white, 7 red and 4 black balls. If four balls are drawn one by one with replacement, what is the probability that none is white. -Maths 9th
Last Answer : Let A, B, C, D denote the events of not getting a white ball in first, second, third and fourth draw respectively. Since the balls are drawn with replacement, therefore, A, B, C, D are independent events such that P (A) = P (B) ... x \(rac{11}{16}\) x \(rac{11}{16}\) = \(\big(rac{11}{16}\big)^4.\)
Description : From a cask of milk containing 45 litres, 9 litres are drawn out and the cask is filled up with water.If the same process is repeated a second, then a third time, what will be the number of litres of milk left in the cask? a) 31.2 b) 20.9 c) 23.04 d) 12.39 e) 15.36
Last Answer : C where x is the initial quantity of milk in the cask y is the quantity of milk withdrawn in each process and n is the number of processes. Initial quantity:45 Withdrawn quantity=9 number of times repeated=3 ... ] Quantity of milk left after the 3rd operation =45*(45-9)/45)^3 = 23.04 litres.
Description : 6 pens and 14 exercise books cost Rs.162. 5pens and 8 exercise books cost Rs.102. The ratio of cost of 1 pen to that of 1 exercise book is : a) 10 : 3 b) 2 : 3 c) 3 : 2 d) 5 : 6 e) None of these
Last Answer : Let cost of 1 pen be Rs.x and that of 1 exercise book be Rs.y. Then 6x +14 y = 162 =>3x + 7y =81……..(1) 5x + 8y =102…………………………………………..(2) (1)× 5 – (2) × 3 =>11y=99=>y=9.Putting y=9 in equation (1),we get : x = 6 x : y =6 : 9 =2 : 3 Answer: b)
Description : 79.93 × 35.02 -59.93 × 85.08 + 74.98 × 44.04 =? a) 1420 b) 1000 c) 1580 d) 870 e) 1260
Last Answer : ? ≈ 80 × 35-60 × 85 + 75 × 44 =2800 – 5100 + 3300 = 1000 Answer: b)
Description : 119 + 784 ÷ 32 x 116 = ? a) 2961 b) 3121 c) 2564 d) 2861 e) 2941
Last Answer : 119 + 784 ÷ 32 x 116 = ? Sol: 119 + 24.5 x 116 =? 119 + 2842 = ? ? = 2961 Answer: a)
Description : When a number is divided by 36, it leaves a remainder of 19. What will be the remainder when the same number is divided by 12? a) 17 b) 7 c) 34 d) 19
Last Answer : b) 7
Description : Find the sum of divisors of 544 which are perfect squares. a) 32 b) 64 c) 68 d) 21
Last Answer : d) 21
Description : A building which is 64 meters high casts a shadow of length 96 meters. The height of a telephone tower which casts a shadow of 180 meters under similar conditions will be a) 100m b) 120m c) 180m d) 96m
Last Answer : b) 120m
Description : What is the highest power of 3 in 165!? a) 80 b) 81 c) 79 d) 73
Last Answer : b) 81
Description : Which one of the following numbers can be removed from the set S= {0,2,4,5,9}, without changing the average of the set? a) 0 b) 2 c) 4 d) 5
Last Answer : c) 4
Description : A can do a work in 15 days and B in 20 days. If they work together for 4 days, then the fraction of work that is left is a) 7/15 b) 8/10 c) 8/15 d) 7/20
Last Answer : c) 8/15
Description : Twenty workers can complete a piece of work in 30 days. After how many days should 5 workers leave the job so that the work is completed in 35 days? a) 5 days b) 10 days c) 15 days d) 20 days
Last Answer : c) 15 days
Description : Two trains are running in opposite direction with the same speed. If the length of each train is 135 meters and they cross each other in 18 seconds, the speed of each train is a) 29km/hr b) 35km/hr c) 27km/hr d) 28km/hr
Last Answer : c) 27km/hr
Description : A trader mixes Ariel detergent costing Rs. 64 per kg with “Surf excel” which costs Rs. 76per kg in the ratio 1:3. If the cost of Surf excel drops to Rs.74 per kg, then in what ratio should he mix the two to leave the cost of mixture unchanged? a) 1:9 b) 1:8 c) 9:1 d) 8:1
Last Answer : a) 1:9
Description : From a total of six men and four ladies, a committee of three is to be formed. If Mrs.X is not willing to join the committee in which Mr.Y is a member, whereas Mr.Y is willing to join the committee only if Mrs.Z is included. How many such committees are possible? a) 138 b) 128 c) 112 d) 91
Last Answer : d) 91