A merchant marks his goods up by 50% and then offers a discount of 10% on the marked price. What % profit does the merchant make after the discount?
Choose one:
A) 21 % B) 25 % C) 69 % D) 35 % E) 19 %

Rationale: "let the price be 100 . the price becomes 150 after a 50 % markup . now a discount of 10 % on 150 . profit = 135 - 100 35 % answer d"
Answer: D