A material is purchased for Rs. 600. If one fourth of the material is sold at a loss of 20% and the remaining at a gain of 10%, Find out the overall gain or loss percentage

Correct Answer : A.

We need to get the Total selling price to solve this question. Because after getting selling price we can get profit or loss, then we can calculate profit% or loss%
So lets solve this:
Price Received by selling one fourth of the material at a loss of 20% =
$(1/4) * 600 * (80/100) = Rs. 120$
Price Received by remaining material at a gain of 10% = 
$(3/4) * 600 * (110/100) = Rs. 495 [Note: 1-(1/4) = 3/4]$
Total Selling Price $= 120 + 465 = Rs. 615$
Profit $= 615 - 600 = 15$
                         $$\begin{gathered} Profit\%=\left(\frac{Gain}{Cost}*100\right) \% \\ =\left(\frac{15}{600}*100\right) \% \\ =\frac{5}{2}\% =2\frac{1}{2}\% \end{gathered}$$