A box contains 21 cards numbered 1, 2, 3, 4, ……………, 21 and thoroughly mixed. A card is drawn at random from this box. What is the probability that the number on the card is divisible by 2 or 3 ?

Total number of possible outcomes = 21 (i.e., 1, 2, 3, 4, ……………, 20, 21)

Number of favourable outcomes (Getting the number on the card that is divisible by 2 or 3) = 14 (2, 3, 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 21)

P(Getting the number on the card that is divisible by 2 or 3) = $\dfrac{\text{Number of favourable outcomes}}{\text{Total number of possible outcomes}}$

= $\dfrac{14}{21}$

= $\dfrac{2}{3}$

Hence, the probability of getting the number on the card that is divisible by 2 or 3 is $\dfrac{2}{3}$.