The sale price of a trolley bag including the sale tax is Rs. 1120. The rate of sale tax is 12% . If the shopkeeper has made a profit of 25%, the cost price of the trolley bag is:  Choose the correct answer: A) rs 1000 B) rs 1515 C) rs 800 D) rs 900 E) none of these

Rationale: "explanation : 112 % of s . p . = 1120 s . p . = rs . ( 1120 x 100 / 112 ) = rs . 1000 . c . p . = rs ( 100 / 125 x 1000 ) = rs 800 . answer : c"
Answer: C