Question

Tick (✓) the correct answer:
The ratio of cost price and selling price of an article is 20 : 21. What is the gain per cent on it?
(a) 5%
(b) $5\frac{1}{2}\%$
(c) 6%
(d) $6\frac{1}{4}\%$

Answer 1

(a) 5%
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$$\begin{gathered} \mathrm{CP}=\mathrm{Rs}.20x \\ \mathrm{SP}=\mathrm{Rs}.21x \\ \mathrm{Gain}=\mathrm{Rs}.\left(21-20\right) \\ =\mathrm{Rs}.\mathrm{x} \\ \therefore \mathrm{Gain}\mathrm{percentage}=\left(\frac{\mathrm{gain}}{\mathrm{CP}}\times 100\right)\% \\ =\left(\frac{\mathrm{x}}{20\mathrm{x}}\times 100\right)\% \\ =5\% \end{gathered}$$