What exactly is 20e asking? I originally thought it was asking for the number of positive integers less than 1000 that are divisible by 7 and 11. However, that's what 20c is asking for, so I'm not sure what 20e wants as an answer.
D) is asking for the integers that are divisible by either 11 or 7 or both (77), but e) is asking for how many are divisible by either 7 OR 11 but NOT both.
--mkburges
