Question

There are 15 tickets in a box, each bearing one of the numbers from 1 to 15. One ticket is drawn at random from the box. Find the probability of event that the ticket drawn - shows a number which is a multiple of 5.

Answer 1

Sample Space (S) = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15}
∴ n(S) = 15

Event B: the ticket shows  a number which is a multiple of 5
B = {5, 10, 15 }
∴ n(B) = 3 

∴ P (B) = `"n(B)"/"n(S)" =3/15 =1/5`​

Hence, the probability that the ticket shows  a number which is a multiple of 5 is `=1/5`​.