Probability Quiz Set 001

Advertisement


Your Score
Correct Answers:
Wrong Answers:
Unattempted:

Question 1

A bag contains 2 Red, 8 Blue and 4 Green marbles. What is the probability of drawing a Red marble if 2 marbles are drawn out randomly?

 A

${25/91}$.

 B

$4/14$.

 C

$26/91$.

 D

$30/91$.

Soln.
Ans: a

Total number of marbles is 14. Combinations of 2 marbles that are possible = 14C2 = ${14 × 13}/2$ = 91. If one of the two balls is red, then red + red is one possibility, and 2 × (8 + 4) are the other possibilities. So total favorable outcomes = 1 + 2 × 12 = 25, and the probability is 25/91 = ${25/91}$.


Question 2

A box contains 83 red balls and an unknown number of blue balls. If the probability of drawing a blue ball is 5 times the probability of drawing a red ball, then how many blue balls are there in the box?

 A

415.

 B

420.

 C

410.

 D

425.

Soln.
Ans: a

Let the number of blue balls be x. Chances of drawing a blue ball are $x/{x + 83}$ = 5 × $83/{x + 83}$, which gives x = 5 × 83 = 415.


Question 3

Two players, A and B, play a game. It is known that probability of A's victory is 0.48. What is the probability of B's victory?

 A

0.52.

 B

0.48.

 C

0.5.

 D

0.25.

Soln.
Ans: a

One of the two is going to win. Probability of A's defeat is 1 - 0.48 = 0.52, which is the probability of B's victory.


Question 4

Two players, A and B, play a game. It is known that probability of A's victory is 0.34. What is the probability of B's victory?

 A

0.66.

 B

0.34.

 C

0.5.

 D

0.25.

Soln.
Ans: a

One of the two is going to win. Probability of A's defeat is 1 - 0.34 = 0.66, which is the probability of B's victory.


Question 5

A box contains 20 red balls and an unknown number of blue balls. If the probability of drawing a blue ball is 5 times the probability of drawing a red ball, then how many blue balls are there in the box?

 A

100.

 B

105.

 C

95.

 D

110.

Soln.
Ans: a

Let the number of blue balls be x. Chances of drawing a blue ball are $x/{x + 20}$ = 5 × $20/{x + 20}$, which gives x = 5 × 20 = 100.


buy aptitude video tutorials


Creative Commons License
This Blog Post/Article "Probability Quiz Set 001" by Parveen (Hoven) is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Updated on 2017-06-24.

Posted by Parveen(Hoven),
Aptitude Trainer


Advertisement