In a class of 30 students,25 offer biology , 21 offer physics and each student offer at least one subject of a perfect is selected from the class what is the probability that she offer one subject only?

Answer 1

First, we need to find the number of students who offer only one subject.

Out of the 30 students, 25 offer biology and 21 offer physics. This means that 5 students offer only physics (21 - 5 = 16 students offering both physics and biology).

So, the total number of students offering only one subject is 5 (only offering physics).

The probability of selecting a student who offers only one subject is 5/30 = 1/6.

Therefore, the probability that a randomly selected student offers only one subject is 1/6.