### I sold two watches for Rs. 300 each, one at loss of 20% and other at the profit of 20%. What is the percentage of loss (-) or profit (+) that resulted from the transaction?

A. (+)4 B. (-)1 C. (+)1 D. (-)4 Answer: Option D
In such cases, loss always occurs. It can be calculated by this formula, $\begin{array}{l}=\frac{\text{ (loss or gain percentage) }^2}{100}=4\\ ie\ 4\%\ \text{ of loss}\end{array}$