I purchased 120 exercise books at the rate of Rs. 3 each and sold 1/3 of them at the rate of Rs. 4 each, 1/2 of them at the rate of Rs. 5 each and the rest at the cost price. My profit percent is -

Answer: Option C

Total C.P. = Rs. (120 × 3) = Rs. 360
Total S.P. = Rs. (40 × 4 + 60 × 5 + 20 × 3) = Rs. 520
Profit = Rs. (520 - 360) = Rs. 160
$$\begin{array}{rl}& \therefore \text{Profit}\%\\ & =\left(\frac{160}{360}\times 100\right)\%\\ & =\left(\frac{400}{9}\right)\%\\ & =44\frac{4}{9}\%\end{array}$$