A retailer bought a hat at wholesale and marked it up 60% to its initial price of $24. By how many more dollars does he need to increase the price to achieve a 100% markup? Choose the correct choice from the following
A) 3  B) 4  C) 5  D) 6  E) 7

Rationale: "let x be the wholesale price . then 1.6 x = 24 and x = 24 / 1.6 = 15 . to achieve a 100 % markup , the price needs to be $ 30 . the retailer needs to increase the price by $ 6 more . the answer is d ."
Answer: D