Tickets numbered 1 to 20 are mixed up and then a ticket is drawn

GIVEN: Tickets are marked from 1 to 20 are mixed up. One ticket is picked at random.

TO FIND: Probability that the ticket bears a multiple of 3

Total number of cards is 20

Cards marked multiple of 3 number are 3,6,9,12,15,18

Total number of cards marked multiple of 3 are 6

We know that PROBABILITY = 

Hence probability of getting a multiple of 3 on the ticket =

Hence probability of getting a multiple of 3 on the ticket