A farmer bought toffees at 6 for a rupee. How many for a rupee must he sell to gain 20 %?

A: 3

B: 5
C: 4

D: 6Solution:
C P of 6 toffees = Rs 1
S.P of 6 toffees
=120% of Rs.1 = Rs 6/5
For Rs 6/5 ,toffees sold= 6.
For Rs 1 toffee sold,= 6 x 5/6 = 5