A dealer sells his goods at a profit of 20%, but uses a weight of 800 g in place of a kg weight. Find his real gain percentage.

Solution (By Examveda Team)

Selling price of 800 g goods with 20% profit $$ = \frac{{1000\left( {100 + 20} \right)}}{{100}} = {\text{Rs}}{\text{. }}1200$$
Cost price of 800 g goods = Rs. 800
Gain = Selling price - Cost price = 1200 - 800 = 400
$$\eqalign{ & {\text{Gain }}\% = \frac{{400}}{{800}} \times 100\% \cr & = \left( {0.5 \times 100} \right)\% \cr & = 50\% \cr} $$
∴ His real gain percentage is 50%