how did you choose A then? I am curious.
This is a very easy question to solve logically. There are 5 answers ranging from 20 to 52. By the type of question asked, the answer must be at one end of the range or another (think about this). Well, the number CAN clearly be 52 so the answer must be at the other extreme 20.
Another way to think of it is "what is the minimum number that can be both"? and the anwers can be found using a Venn Diagram technique but it will take a little longer.
Former Senior Instructor, Manhattan GMAT and VeritasPrep
Vice President, Midtown NYC Investment Bank, Structured Finance IT
MFE, Haas School of Business, UC Berkeley, Class of 2005
MBA, Anderson School of Management, UCLA, Class of 1993