Let S be a set of 71 consecutive integers. 15 numbers in S are divisible by 5, and 11 numbers in S are divisible by 7. How many numbers in S are divisible by 35?
The first number must start with a multiple of 5 since 71/5<15.Also the first number is divisible by 7 since 71/7<11 so there are |71/35|+1 numbers that are divisble by 35 which is 3
