How many integers from 1 to 1000 are divisible by 30 but not

How many integers from 1 to 1000 are divisible by 30 but not by 16?

Solution

number of integers from 1 to 1000 divisible by 30 is 33

numbers divisible by both 30 and 16 are divisible by 240

nuumber of integers from 1 to 1000 divisible by 240 is 4

umber of integers from 1 to 1000 divisible by 30 by not by 16= 33-4 =29