When sold at a 60% discount, a sweater nets the merchant a 20% profit on the wholesale cost at which he initially purchased the item. By what % is the sweater marked up from wholesale at its normal retail price?
Options.
A) 20 % B) 40 % C) 66.67 % D) 80 % E) 100 %

Rationale: "we should be careful about what are we measuring % on / what is the base . . let the marked up price = 100 . . selling price = 100 - 60 % of 100 = 40 . . profit = 20 % . . therefore the wholesale purchase cost = x . . . . 1.2 x = 40 or x = 33.33 . . . marked price was 100 so . . . so answer is 66.67 % . . c"
Answer: C