Question

In a school, there are 1000 students, out of which 430 are girls. It is known that out of 430, 10% of the girls study in class Xll, What is the probability that a student chosen randomly students in Class Xll given that the chosen student is a girl ?

Answer 1

Given

Number of girls in class XII=10% of total girls

$=\frac{10}{100}\times 430=43girls$

Consider the following events

A=student chosen from class XII

B=Chosen student is a girl

Then the rquired probablity$=\frac{P(A\cap B)}{P\left(B\right)}=\frac{\frac{43}{1000}}{\frac{430}{1000}}=\frac{1}{10}$