A retailer bought a shirt at wholesale and marked it up 80% to its initial price of $45. By how many more dollars does he need to increase the price to achieve a 100% markup?
Choose the correct choice from the following answers.
A) 1
B) 2
C) 3
D) 4
E) 5

Rationale: "x is the buy price . x + 80 % x = 1,8 x is the sale price = 45 so x , the buy price becomes 45 / 1,8 = 25 % 100 mark up means x + 100 % x = 2 x so 50 . 50 - 45 = 5 answer : e"
Answer: E