# Probability Quiz Set 006

### Question 1

If P(E) = 0.28, then what is the probability of non-occurrence of E?

A

0.72.

B

0.28.

C

0.5.

D

0.25.

Soln.
Ans: a

P(E) + P(non-occurrence of E) is always = 1. So P(non-occurrence of E) = 1 - P(E) = 0.72.

### Question 2

A class has 3 boys and 2 girls. What is the probability of choosing 1 boy and 2 girls?

A

\${3/10}\$.

B

\$4/5\$.

C

\$4/10\$.

D

\$8/10\$.

Soln.
Ans: a

Three students have to be picked. Total number of ways = 5C3 = \${5 × 4 × 3}/{3 × 2 × 1} = \$10. Number of ways of picking 1 boy and 2 girls = 3C1 × 2C2 = 3. So probability = \$3/10\$ = \${3/10}\$.

### 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

\$9/11\$.

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

45 defective pens are accidentally mixed with 40 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

\${9/17}\$.

B

\$47/85\$.

C

\$10/85\$.

D

\$14/85\$.

Soln.
Ans: a

Out of the total number of pens = 85, the chances favoring defective pen are 45. So the probability is 45/85 = \${9/17}\$.

### Question 5

What is the probability of getting a multiple of 2 when a dice is tossed in the air?

A

1.

B

1/2.

C

1/4.

D

0.

Soln.
Ans: b

Total outcomes are 6. The number of favorable chances are three: 2, 4, 6. So probability is 3/6 = 1/2. 