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
I got (D) 220 and (E) 208, does this look right to anyone else?
--Rhollowe 17:49, 28 January 2009 (UTC)
For clarification for the person who originally posted in bold, 20c is asking for positive integers less than 1000 that are divisible by 7 AND 11 both. For example, 154 is divisible by 7 and also divisible by 11. So because 7 and 11 have no common multiples this is basically all numbers divisible by 77. --Kristen