What is the number of integers from 1 to 1000 (inclusive) that are divisible by neither 15 nor by 20?  Choose the correct choice
A) 887
B) 678
C) 765
D) 345
E) 256

Rationale: "in 1000 consecutive numbers , number of multiples of 15 = 1000 / 15 = 66 ( ignore decimals ) in 1000 consecutive numbers , number of multiples of 20 = 1000 / 20 = 50 number of multiples of 15 * 20 i . e . 300 = 1000 / 300 = 3 number of integers from 1 to 1000 that are divisible by neither 15 nor by 20 = 1000 - ( 66 + 50 - 3 ) { using the concept of sets here ) = 887 answer is a"
Answer: A