Question

A math teacher gave her students two tests. On the first test, 80% of the class passed the test, but only 30% of the class passed both tests.

What is the probability that a student passes the second test, given that they passed the first one?




0.256

0.375

0.500

0.625

Answer 1

0.375 is answer

Explanation:

Given that the math teacher gave her students two tests. On the first test, 80% of the class passed the test. But only 30% of the class passed both tests.

Let A - the students pass I test

B = students pass second test

Then P(A) = 80%=0.8 and P(AB) = 30% =0.30

Required probability =probability that a student passes the second test, given that they passed the first one

= P(B/A) = P(AB)/P(A)

= 0.30/0.80

=3/8

=0.375

Right answer is 0.375