Aptitude - Probability

A man has nine friends, four boys and five girls. In how many ways can he invite them, if there have to be exactly three girls in the invitees?

A.  320

B.  160

C.  80

D.  200

View Answer  

Correct Answer :

160



Explanation :
No Explanation available for this question

The weights in kilograms of 10 students are 52, 45, 31, 35, 40, 55, 60, 38, 44, 36. If 44 is replaced by 46 and 40 is replaced by 35 then new median will be

A.  42

B.  40.5

C.  40

D.  41.5

View Answer  

Correct Answer :

41.5



Explanation :
No Explanation available for this question

The probability that a card drawn from a pack of 52 cards will be a diamond or a king is:

A.  2/13

B.  4/13

C.  1/13

D.  1/52

View Answer  

Correct Answer :

4/13



Explanation :
No Explanation available for this question

Shiwani thought of a two-digit number and divided the number by the sum of the digits of the number. He found that the remainder is 3. Devesh also thought of a two-digit number and divided the number by the sum of the digits of the number. He also found that the remainder is 3. Find the probability that the two digit number thought by Shiwani and Devesh is TRUE?

A.  1/15

B.  1/14

C.  1/13

D.  1/12

View Answer  

Correct Answer :

1/14



Explanation :
No Explanation available for this question

In a lottery there are 10 prizes and 25 blanks. A lottery is drawn at random. What is the probability of getting a prize?

A.  1/10

B.  2/5

C.  2/7

D.  5/7

View Answer  

Correct Answer :

2/7



Explanation :
No Explanation available for this question

A number is selected at random from first thirty natural numbers. What is the chance that it is a multiple of either 3 or 13?

A.  17/30

B.  2/5

C.  11/30

D.  4/15

View Answer  

Correct Answer :

17/30



Explanation :
No Explanation available for this question

Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?

A.  1/2

B.  2/5

C.  8/15

D.  9/20

View Answer  

Correct Answer :

9/20



Explanation :
No Explanation available for this question

Two urns contain 5 white and 7 black balls and 3 white and 9 black balls respectively. One ball is transferred to the second urn and then one ball is drawn from the second urn. Find the probability that the first ball transferred is black, given that the ball drawn is black?

A.  13/23

B.  11/23

C.  14/23

D.  7/23

View Answer  

Correct Answer :

14/23



Explanation :
No Explanation available for this question

A box contains 9 red toys, 7 green toys and 9 blue toys. Each ball is of a different size. The probability that the red ball being selected is the smallest red toy, is:

A.  1/9

B.  2/21

C.  1/25

D.  6/25

View Answer  

Correct Answer :

1/9



Explanation :
No Explanation available for this question

N persons stand on the circumference of a circle at distinct points. Each possible pair of persons, not standing next to each other, sings a two-minute song one pair after the other. If the total time taken for singing is 28 minutes, what is N?

A.  5

B.  7

C.  9

D.  None of these

View Answer  

Correct Answer :

7



Explanation :
No Explanation available for this question

Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?

A.  1/2

B.  2/5

C.  8/15

D.  9/20

View Answer  

Correct Answer :

9/20



Explanation :
No Explanation available for this question

Let x = 3a + 3b, where a and b are chosen independently from the integers1 through 100 inclusive (with each integer having an equal likelihood of being chosen). Compute the probability that x is an integral multiple of 5.

A.  1/2

B.  1/3

C.  5/6

D.  1/4

E.  none of these

View Answer  

Correct Answer :

1/4



Explanation :
No Explanation available for this question

From 7 men and 5 ladies a committee of 4 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 in all are possible?

A.  366

B.  375

C.  450

D.  495

View Answer  

Correct Answer :

366



Explanation :
No Explanation available for this question