# Probability Quiz Set 013

### Question 1

A bag contains three marbles 4 Red, 5 Green and 3 Blue. One marble is taken out. What is the probability of drawing a red marble.

A

1/3.

B

5/12.

C

1/4.

D

4/9.

Soln.
Ans: a

Total ways of drawing a marble = 4 + 5 + 3 = 12. Of these red marble can be drawn in 4 ways. So required probability = 4/12 = 1/3.

### Question 2

49 defective pens are accidentally mixed with 84 good ones. It is not possible to just look at a pen and tell whether it is defective or not. One pen is taken out at random. What is the probability that it is a defective pen?

A

\${7/19}\$.

B

\$51/133\$.

C

\$8/133\$.

D

\$12/133\$.

Soln.
Ans: a

Out of the total number of pens = 133, the chances favoring defective pen are 49. So the probability is 49/133 = \${7/19}\$.

### Question 3

From a deck of 52 cards 1 card is drawn at random. What is the probability that it will be a red "8"?

A

\${1/26}\$.

B

\$6/8\$.

C

\$2/26\$.

D

\$6/26\$.

Soln.
Ans: a

Number of ways of drawing 1 card = 52. There are two red "8" in the whole pack. So favorable chances are 2. Probability = 2/52 = 1/26.

### Question 4

A box contains 7 navy, 2 khaki and 3 orange balls. What is the probability of drawing a ball that is neither khaki nor navy?

A

\${1/4}\$.

B

\$4/12\$.

C

\$2/66\$.

D

\$6/66\$.

Soln.
Ans: a

Total number of marbles is 12. We have to basically find the probability of picking a orange ball, for which 3 chances are favorable. So probability = 3/12 = \${1/4}\$.

### Question 5

9 cones are lying inverted on a table. 2 of them contain balls, but 7 of them are empty. What is the probability of getting a ball if one of the cones is opened randomly?

A

\${2/9}\$.

B

\$3/9\$.

C

\$4/9\$.

D

\$7/9\$.

Soln.
Ans: a

Chances favoring a ball are 2, whereas the total chances are 9. The probability is 2/9 = \${2/9}\$. 