Question

The probability of getting a two digit number from first $100$ natural number is

Answer 1

Let $S=\{1,2,3,...,98,99,100\}$

$\therefore n\left(S\right)=100$

Let $A$ be the possibility of getting two digit number.

$\Rightarrow A=\{10,11,12,13,...,98,99\}$

$\therefore n\left(A\right)=90$

Probability of getting a two digit number $P\left(A\right)=\frac{n\left(A\right)}{n\left(S\right)}=\frac{90}{100}=\frac{9}{10}$