A box contains 20 cards numbered from 1 to 20. A card is drawn at random from the box. The probability that the number on the drawn card is divisible 2 or 3 is

Numbers divisible by “2” from 1 to 20

$=\left\{2,4,6,8,10,12,14,16,18,20\right\}=10$

Numbers divisible by “3” from 1to 20

$=\left\{3,6,9,12,15,18\right\}=6$

Number divisible by ‘2’ & ‘3’ are $=\left\{6,12,18\right\}=3$

The number divisible by “2” (or) “3”

$n\left(E\right)=10+6-3=13$

Probability $P\left(E\right)=\frac{n\left(E\right)}{n\left(s\right)}=\frac{13}{20}$