Question

In a class, 60% of the students read mathematics, 25% biology and 15% both mathematics and biology. One student is selected at random. What is the probability that he reads mathematics if it is known that he reads biology?

A. \(\frac{2}{5}\)

B. \(\frac{3}{5}\)

C. \(\frac{3}{8}\)

D. \(\frac{5}{8}\)

Answer 1

Correct answer is B.

Given:

60% of the students read mathematics, 25% biology and 15% both mathematics and biology

That means,

Let the event A implies students reading mathematics,

Let the event B implies students reading biology,

Then, P(A) = 0.6

P(B) = 0.25

P(A∩B) = 0.15

We, need to find P(A/B) = P(A∩B)/ P(B)

\(\Rightarrow\) \(\frac{0.15}{0.25}=\frac{3}{5}\)