Of the crates in a warehouse, 4/11 contain apples. If 1/4 of the crates containing apples are sold, which of the following is closest to the percentage of the remaining crates that will contain apples?
The actual math involved in this question isn't particularly complex. At the same time, this question exemplifies the fact that, to get GMAT questions correct, we have to be careful not to get fooled by any tricky aspects of a question and to answer the question asked, which in this case is what percentage of the REMAINING crates will contain apples.
Here's one approach that works.
Initial situation:
4/11 of crates contain apples
Situation after 1/4 of the apples are sold:
1/11 of the original crates have been sold.
10/11 of the original crates remain.
3/11 of the original crates still remain and contain apples.
(3/11)/(10/11) = 3/10 = 30%
(A) 27
(B) 30
(C) 70
(D) 75
(E) 91
Correct answer: B