Question:
Tick (✓) the correct answer:
On selling an article at a certain price a man gains 10%. On selling the same article at double the price, gain per cent is
(a) 20%
(b) 100%
(c) 120%
(d) 140%
Solution:
(c) 120%
Let the SP and CP of the article be Rs x and y, respectively.
Gain percentage = 10%
$\Rightarrow 10=\frac{x-y}{y} \times 100$
$\Rightarrow \mathrm{y}=\frac{10 x}{11}$
According to the question, we have:
SP = Rs 2x
$\therefore$ Gain percentage $=\frac{\text { gain }}{\mathrm{CP}} \times 100$
$=\frac{2 x-\frac{10 x}{11}}{\frac{10 x}{11}} \times 100$
$=\frac{12}{10} \times 100$
$=120 \%$