Patrick purchased 70 pencils and sold them at a loss equal to the selling price of 20 pencils. The cost of 70 pencils is how many times the selling price of 70 pencils? Choose the correct choice from the following answers
A) 0.75	B) 0.8	C) 1	D) 1.28	E) 1.35

Rationale: "say the cost price of 70 pencils was $ 70 ( $ 1 per pencil ) and the selling price of 1 pencil was p . selling at a loss : 70 - 70 p = 20 p - - > p = 7 / 9 . ( cost price ) / ( selling price ) = 1 / ( 7 / 9 ) = 9 / 7 = 1.28 . answer : d ."
Answer: D