In Class XI of a school 40% of the student’s 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.

Let A be the event that the student is studying mathematics and B be the event that the student is studying biology.

And , is probability of studying both mathematics and biology.

Here, Probability of studying mathematics or biology will be given by P (A∪B)

is the probability that the student will studying mathematics or biology