Sorry if this was posted before, but I couldn't find it on the forum.
Store S sold a total of 90 copies of a certain book during the 7 days of last week, and it sold different numbers of copies on any 2 of the days. If for the 7 days store S sold the greatest number of copies on Saturday and the second greatest number of copies on Friday, did Store S sell more than 11 copies on Friday?
1) Last week Store S sold 8 copies of the book on Thursday
2) Last week store S sold 38 copies of the book on Saturday
I think it's clear that (1) is not suff. by itself:
For (1): (M, T, W, Th, S, F,Sa) could be (1,2,3,4,8,11,61) or (1,2,3,4,8,12,60)
For (2): Such a small value of S would seem to force F be be largeish. Suppose that F is not greater than 11. Thus F+Sa <=49 and M+T+W+Th+S>=41 But the largest possible sum, given that F is at most 11, would be 10+9+8+7+6=40. This contradiction implies that our supposition was wrong, that is F must be greater than 11. SUFF
My answer: B