If 'y' is a positive integer exactly divisible by 4 or 5 but not divisible by 8.What could possibly be the value of 'y' ?  Choose the correct answer
A) 40  B) 80  C) 20  D) 24  E) 36

Rationale: 40 and 80 are both divisible by 4 and 5 but also by 8 . so they are not the right answer . 24 and 36 are both clearly not divisible by 5 ( not correct ) 20 is both divisible by 4 and 5 but not by 8 . answer : ( c )
Answer: C