A vendor bought toffees at 6 for a rupee. How many for a rupee must he sell to gain 30%?  Choose the correct choice from the following choices.
A) 1 / 2  B) 2 / 6  C) 3 / 6  D) 9 / 6  E) 15 / 2

Rationale: c . p . of 6 toffees = re . 1 s . p . of 6 toffees = 180 % of re . 1 = rs . 9 / 5 for rs . 9 / 5 , toffees sold = 6 . for re . 1 , toffees sold = 9 x 5 / 6 = 15 / 2 . answer e
Answer: E