A retailer bought a hat at wholesale and marked it up 70% to its initial price of $34. By how many more dollars does he need to increase the price to achieve a 100% markup? Select the correct option
A) 2
B) 4
C) 6
D) 8
E) 10

Rationale: let x be the wholesale price . then 1.7 x = 34 and x = 34 / 1.7 = 20 . to achieve a 100 % markup , the price needs to be $ 40 . the retailer needs to increase the price by $ 6 more . the answer is c .
Answer: C