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 or both.

Answer

N/a

Explanation

Let `M=` event of studying maths and
`B=` event of studying biology
`:. P(M)=40%=40/100=0.4`
`P(B)=30%=30/100=0.3`
and `P(MnnB)=10%=10/100=0.1`
Now event the selecting student is studying Maths or Biology.
`=MuuB`
`:.P(MuuB)=P(M)+P(B)-P(MnnB)`
`=0.4+0.3-0.1=0.6`