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 $XII$. The probability that a student chosen randomly studies is in class $XII$ given that the chosen student is a girl:

• A. $0.4$
• B. $0.43$
• C. $0.1$
• D. $0.41$

Answer 1

The correct option is C $0.1$

Let $E$ denotes the event that a student chosen randomly studies in class $XII$ and $F$ be the event that the randomly chosen student is a girl.
Now, $P\left(F\right)=\frac{430}{1000}=0.43$ and $P(E\cap F)=\frac{43}{1000}=0.043$
Then $P\left(E/F\right)=\frac{P(E\cap F)}{P\left(F\right)}=\frac{0.043}{0.43}=0.1$