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) $6 \frac{1}{4} \%$
Solution:
(a) $5 \%$
$\mathrm{CP}=$ Rs. $20 x$
$\mathrm{SP}=$ Rs. $21 x$
Gain = Rs. $(21-20)$
= Rs. X
$\therefore$ Gain percentage $=\left(\frac{\text { gain }}{\mathrm{CP}} \times 100\right) \%$
$=\left(\frac{x}{20 x} \times 100\right) \%$
$=5 \%$