Solution:
Let M and B denote the student of Mathematics and Biology.
Given,
[10% of the class study both subjects i.e. they ate common in both subjects]
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.
Let M and B denote the student of Mathematics and Biology.
Given,
[10% of the class study both subjects i.e. they ate common in both subjects]