Question

A box contains cards number from $1$ to $20$. A cards is drawn at random from the box. Find probability that number on the drawn card is a composite number

Answer 1

Composite number from $1$ to $20$ are $\{4,6,8,9,10,12,14,15,16,18,20\}$

$P\left(Compositenumber\right)=\frac{11}{20}$