91Ó°ÊÓ

In Class XI of a school \(40 \%\) of the students study Mathematics and \(30 \%\) study Biology. \(10 \%\) of the class study both Mathematics and Biology. If a student is selected at random from the class, find the probability that he will be studying Mathematics or Biology.

In an entrance test that is graded on the basis of two examinations, the probability of a randomly 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?