Question

a number is picked from the set {1,2,3,-,18}.find the probability that it is either a multiple of 3 or a number less than 7

Answer 1

Maths

Answer 2

"...either a multiple of 3 or a number less than 7"

only 2 elements satisfy that condition, namely the 3 and 6

so prob(of your event) = 2/18 = 1/9