Question

A dishonest trader using a faulty balance makes a profit of $5\%$ while buying as well as while selling his goods. What is his actual gain percent in the whole process?

Answer 1

Let the actual cost of goods be ₹ 100.

While buying the trader makes a $5\%$ profit. That means he buys ₹ 105 worth of goods by paying ₹ 100.

While selling he makes again a profit of $5\%$ on ₹ 105

Applying the second profit of $5\%$ on ₹ 105, we get SP $=₹105(1+0.05)=₹105\times 1.05=₹110.25$

So the net profit is,

110.25 − 100 = ₹ 10.25.

$\text{Profit}\%=\frac{\text{profit}}{\text{Cost price}}\times 100$

$\text{Profit}\%=\frac{10.25}{100}\times 100$

$=10.25\%$

So, the gain per cent in the whole process amounts to $10.25\%$