If a number is selected at random out of the first 120 natural numbers, then the probability that it is divisible by 5 or 8 is

Numbers out of the first 120 that are divisible by 5 = (120/5)=24

Numbers out of the first 120 that are divisible by 8 = (120/8)=15

So, the numbers that are divisible by 5 or 8 = 24+15= 39

But, these 39 numbers also includes the numbers which are divisible by both 5 and 8.

Therefore we need to subtract these numbers.

Numbers out of the first 120 that are divisible by both 5 and 8

= 120/(5*8)= 120/40=3

  Thus , Numbers out of the first 120 that are divisible by 5 or 8 = 39-3=36

Probability of the event required =36/120

                                                        =3/10  Ans.