PROBABILITY

1.The probability that a digit chosen at random from {1,2,3,4,5,6,7,8,9} will be multiple

  of 3 is

  a)1/3 b)2/3   c)3/4   d)5/9

2.The probability of throwing a total of 3 when two dice are thrown is

  a)1/36       b)1/18  c)5/36  d)35/36

3.If two cards are drawn are at random from a well shuffled pack , the probability that

  both are queens is

  a)3/221      b)1/221 c)1/17  d)4/17

4.A committee of three is to be chosen from a group of 3 men and 4 women.The probability 

  of all the three being women is

  a)4/35       b)3/35  c)31/35 d)34/35

5.If 5 students are seated at random in a row,the probability that two particular students 

  are not seated side by side is

  a)13/120     b)119/120      c)3/5   d)4/5

6.There are 25 bulbs,out of which 2 are fused.If 2 bulbs are drawn at random the probability

  of drawung one good and one fused bulb is

  a)7/13       b)5/13  c)23/150       d)7/15

7.A puzzle in logic was given to 3 students A,B and C whose chances of solving i are 1/2,3/4 

  and 1/4 respectively.The probability that the problem is solved is..

  a)29/32      b)31/32 c)1/8   d)7/8

8.A die has 2 of its  sides painted pink,2 blue and 2 green.If the die is rolled twice the 

  probability that same colour appears both the times is

  a)1/3 b)2/3   c)7/9   d)8/9

9.If the card is drawn at random from a pack,the probability that it is a jack is

  a)1/52       b)1/26  c)3/26  d)1/13

10.The chance that a leap year has 53 tuesdays is

  a)2/13       b)3/7   c)2/7   d)1/8

11.The odds against an event A are 3 to 2 while the odds in favor of another independent event

   B are 2 to 5.Then the probability that atleast one of them would happen is

  a)5/7 b)2/7   c)4/7   d)3/7

12.The probability of throwing 22 or more with a throw of 4 dice is

  a)5/432      b)431/432      c)3/432 d)427/432

Directions for questions 13  to 17: A house wife buys a dozen eggs of which two turn out to be 

  bad.If she chooses 4 eggs at random from the dozen to scramble for breakfast,the probability

  that she chooses

13.all good eggs is

  a)1/33       b)14/33 c)13/33 d)1/11

14.three good eggs and one bad egg is

  a)16/33      b)1/11  c)19/33 d)10/11

15.two good eggs and two bad eggs is 

  a)17/33      b)16/33 c)3/11  d)1/11

16.atleast one bad egg is

  a)13/22      b)4/11  c)19/33 d)3/11

17.atleast one good egg is

  a)13/22      b)1     c)11/33 d)14/33

18.If three balls are drawn at random from a bag containing 4 red and 7 green balls,the odds in 

   favour of all being red is

  a)12:13      b)4:161 c)161:4 d)3:121

19.The probability that a number selected at random from the first 10 natural numbers is prime,is

  a)3/5 b)3/10  c)7/10  d)2/5

20.The probability of getting exactly 2 heads when 2 coins are tossed is 

  a)1/2 b)1/4   c)3/4   d)1/3

21.The probability of getting atleast one head when 4 fair coins are tossed is

  a)1/16       b)15/16 c)3/16  d)7/16

22.The probability of getting atleast one head,where a loaded coin is tossd twice(given that

   head occurs twice as often as tails) is

  a)7/9 b)8/9   c)4/9   d)2/9

23.The odds,against the ocurance of a head when a loaded coin is tosed are 3:5.The probability of 

   getting a tail when the coin is tossed is

  a)3/8 b)5/8   c)3/2   d)5/2

24.If 4 coins are tossed,the probability of getting 2heads and 2 tails is

  a)3/8 b)6/11  c)2/5   d)4/5

25.If A and B are two mutually exclusive events such that P(A)=5 P(B),then P(AUB):P(B)=

  a)6:1 b)5:6   c)6:11  d)5:11

26.if P(A) = p and P(B)=q,then P(A`UB`)(when A and B is independent) is

  a)pq  b)(1-p)(1-q)   c)1-pq  d)none

27.If P(A) = 1/4,P(B)=2/5 and P(AUB) = 1/2, then P(A intersection B) is 

  a)0.15       b)0.10  c)0.12  d)0.32

28.If P(A) = 0.75 and B is an event which is mutually exclusive with A,P(A intersection B)=

  a)0.25       b)0.35  c)0.81  d)none

29.A bag contains 7 green and 8 white balls.If two balls are drawn simutaneously,the probability

   that both are of the same colour is

  a)8/15       b)7/15  c)3/5   d)8/15

30.If 3 dice are thrown, the probability of getting an even number on each die is

  a)4/9 b)3/4   c)3/16  d)1/8

31.Two dice are rolled.The probability of getting a sum of atleast 9 is

  a)13/36      b)5/18  c)35/36 d)11/36

32.The odds against Arun solving a problem are 5:7 and the odds in favor of Prashant solving

   the same problem are 4:3.The probability that only one of them can solve the problem is

  a)13/84      b)41/84 c)17/84 d)23/84

33.If a card is drawn from a well shuffled pack of cards,the kprobability of drawing a spade

   or a king is

  a)19/52      b)17/52 c)5/13  d)4/13

34.Out of first 20 natural numbers,one number is picked at random.The probability that it is 

   wither an even number or a prime number is

  a)1/2 b)16/19 c)4/5   d)17/20

35.A bag has 10 bulbs of which 3 are defective.If three bulbs are drawn in succession without 

   replacement,the prabability of all the three being defective is

   a)(3/10)^3  b)1/120 c)1/80  d)7/120

36. If P(Aintersection B) = 0.2,P(A)=0.5 and P(AUB) = 0.7then P(B`)=

   a)0.4       b)0.8   c)0.6   d)0.3

37.In a single throw with two dice,the probability of throwing the sum less than 11 is

   a)11/12     b)35/36 c)31/36 d)3/4

38.If two cards are drawn at random from a well shuffled pack,the probability that both are

   king is

   a)1/221     b)13/17 c)51/52 d)5/52

39.If six persons sit around a table, the probability that some specified three of them are 

   always together is

   a)1/20      b)3/10  c)1/5   d)4/5

40.Arun speaks truth in 70% of cases while Bhargav speaks truth in 65% of cases.The probability

   that they will contradict each other on starting the same fact is

   a)0.44      b)0.72  c)0.47  d)0.86