There are 11 letters in total.
T & B
T = 1/11
B = 2/11
The total probability is 3/11.
Answer:3
Step-by-step explanation:
Given
There are total 40 students in a class
No of students with Pierced Nose n(N)=7
No of students with Pierced ear n(E)=36
and we know using sets
where Students either nose or ear Pierced
no of students having both nose and ear pierced