Question

If the cost price of 21 watches is equal to the selling price of 18 pieces, then what would be the gain percent in this transaction?

• A. $6\frac{1}{2}\%$
  
• B. 7%
  
• C. $6\frac{2}{3}\%$
  
• D. 6%
• E. None of these

Answer 1

The correct option is C $6\frac{2}{3}\%$


Here, m =21, n =18.
$\therefore Gain\%=\left(\frac{m-n}{n}\right)\times 100=\left(\frac{21-18}{18}\right)\times 100=(\frac{3}{18}\times 100)\%=16\frac{2}{3}\%$