Question

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.

Answer 1

`P(M) = (40x)/(100x) = 0.4`
`P(B) = 30/100 = 0.3`
`P(M nn B) = 10% = 0.1`
`P(M uu B) = ?`
so, `P(M uu B) = P(M) + P(B) - P(M nn B)`
`= 0.4+0.3-0.1`
`=0.6 = 60%`
answer