# Probability Quiz Set 020

### Question 1

A box contains 4 maroon, 7 sky blue and 3 dark green balls. What is the probability of drawing a ball that is neither sky blue nor maroon?

A

\${3/14}\$.

B

\$4/14\$.

C

\$4/91\$.

D

\$8/91\$.

Soln.
Ans: a

Total number of marbles is 14. We have to basically find the probability of picking a dark green ball, for which 3 chances are favorable. So probability = 3/14 = \${3/14}\$.

### Question 2

A box contains 8 maroon, 5 navy and 3 pink marbles. What is the probability of drawing a marble that is not pink if 2 marbles are drawn out randomly?

A

\${13/20}\$.

B

\$3/16\$.

C

\$14/120\$.

D

\$18/120\$.

Soln.
Ans: a

Total number of marbles is 16. Combinations of 2 marbles that are possible = 16C2 = \${16 × 15}/2\$ = 120. Chances of drawing a non-pink ball are 13C2 = \$(13 × (13 - 1))/2\$ = 78. So probability = 78/120 = \${13/20}\$.

### Question 3

From a deck of 52 cards two cards are drawn at random. What is the probability that both one is a hearts, and the other a clubs?

A

\${13/102}\$.

B

\$7/9\$.

C

\$14/102\$.

D

\$18/102\$.

Soln.
Ans: a

Number of ways of drawing 2 cards out of 52 = 52C2 = \$(52 × 51)/2\$ = 1326. There are 13 hearts and 13 clubs in the deck. So 2 such cards can be drawn in 13 × 13 = 169 ways. The probability = 169/1326 = 13/102.

### 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

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.