In an entrance test that is graded on the basis of two examinations, the probability of a randomiy chosen student passing the first examination is `0.8` and the probability of passing the second examination is `0.7` . The probability of passing atleast one of them is `0.95` . What is the probability of passing both?

Explanation

Let probability of passing the first examination .=P(A). and probability of passing the second examination .=P(B).
Probability of passing atleast one of them .=P(A. or .P(A)+P(B)-P(A nn B)=0.95.
.P(A nn B)=0.8+0.7-0.95=1.5-0.95=0.55, therefore. Required probability .=0: 55.