A grocer purchases three qualities of lemons at different rates. The first quality was purchased at 2 for Rs. 1, the second at 3 for Rs. 2 and the third at 4 for Rs.3. He sold all the lemons at 5 for Rs. 4. If the ratio of the number of lemons of the three qualities is 1 : 2 : 3, then what is the approximate gain or loss percentage incurred by the grocer?
a. `2. 65 %` `"loss"`
b. `17. 56 %``"loss"`
c. `17. 56 ``"gain"`
d. `18. 65 %` `"gain"`
e. none of these