A shirt goes on sale for 80% of its original price. One week later, the sale price is marked down 20%. The final price is what percent of the original price? Options.
A) 72 %
B) 70 %
C) 52 %
D) 64 %
E) 28 %

Rationale: "just assume original price is 100 . sale price = 80 then it is marked down by 20 % = 80 - 16 = 64 . hence it is 64 % od the original price . hence answer is d ."
Answer: D