Each week Manhattan GMAT posts a GMAT question on our blog and follows up with the answer the next day. Are you up for the challenge?
The numbers of nuts stored by two squirrels, Burl and Shirl, at the beginning of September were in the ratio A : B. At the end of September, the numbers of nuts stored by Burl and Shirl were in the ratio C : D. If Burl had n times as many nuts at the end of September as at the beginning of September, then by what percent did the number of nuts stored by Shirl increase during September?
(A) 
(B) 
(C) 
(D) 
(E) 