Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Probability

Question:

A and B are two candidate seeking admission in a college. The probability that A is selected is 0.7 and the probability that exactly one of them is selected is 0.6. Find the probability that B is selected.

Options:

0.35

0.25

0.45

0.55

Correct Answer:

0.25

Explanation:

Let 'p' be the probability that B gets selected.

P(Exactly one of A, B is selected) = 0.6 (given)

P(A is selected, B is not selected; B is selected, A is not selected) = 0.6

P(A∩B′) + P(A′∩B) = 0.6

⇒ P(A). P(B′) + P(A′). P(B) = 0.6

⇒ (0.7) (1-p) + (0.3)p = 0.6

⇒ p = 0.25