a number is selected at random from the first 60 natural numbers find the probability that it is a multiple of 3 and 5

Total observations: 60
multiples of  3= 20
multiples of  5= 12
Common multiples of 3 and 5 = 15, 30, 45, 60
no. of favourable outcomes= 4



Probability= no. of favourable outcomes/Total no. of outcomes

P(E)          =         4/60
                 =         1/15



Therefore, the probability of getting a number which is a multiple of 3 and 5 is 1/15.