Two sets A and B consists only of positive integers such that mean of set A is 40 . If set R consist of all the elements of both A and B such that mean of R is 80 then the mean of set B is => Choose the correct choice.
A) [A] 65	B) [B] 60	C) [C 70	D) [D] 55	E) [E] cannot be determined
For this question, we have zero information about the size of two sets, sets AB. These two sets may have the same size or may be wildly different. Thus, the answer is (E), the mathematical answer cannot be determined. This is a very weak math question. As someone who writes GMAT practice questions, I would give this a grade of anD-as a question.   Answer [E] cannot be determined
<result>E</result>
Two sets A and B consists only of positive integers such that mean of set A is 40 . If set R consist of all the elements of both A and B such that mean of R is 80 then the mean of set B is =>