Pramod J AskiitiansExpert-IIT-B
number of integers between 1 and 1000 (both inclusive) which are divisible by either of 10, 15 or 25 is
number of integers between 1 and 1000 divisible by 10 is 100
number of integers between 1 and 1000 divisible by 15 is 66
number of integers between 1 and 1000 divisible by 25 is 40
number of integers between 1 and 1000 divisible by 10 and 15 is multiples of 30 and is 30
number of integers between 1 and 1000 divisible by 10 and 25 is multiples of 50 and is 20
number of integers between 1 and 1000 divisible by 25 and 15 is multiples of 75 and is 13
number of integers between 1 and 1000 divisible by 10,15 and 25 is multiples of 150 and is 9
so,
number of integers between 1 and 1000 (both inclusive) which are divisible by either of 10, 15 or 25 is
= 100+66+40-30-20-13+9 = 152