Tick (✓) the correct answer:
A man sold two chairs for Rs 500 each. On one he gains 20% and on the other he loses 12%. His net gain or loss per cent is
(a) 1.5% gain
(b) 2% gain
(c) 1.5% loss
(d) 2% loss
(a) 1.5% gain
SP of the first chair $=$ Rs 500
Gain percentage $=20 \%$
$\therefore \mathrm{CP}$ of the first chair $=\left\{\frac{100}{(100+\text { gain } \%)} \times \mathrm{SP}\right\}$
$=$ Rs. $\left\{\frac{100}{(100+20)} \times 500\right\}$
$=$ Rs. $\left(\frac{100}{120} \times 500\right)$
$=$ Rs. $416.67$
SP of the second chair $=$ Rs. 500
Loss percentage $=12 \%$
$\therefore \mathrm{CP}$ of the second chair $=\left\{\frac{100}{(100-\text { loss } \%)} \times \mathrm{SP}\right\}$
$=$ Rs. $\left\{\frac{100}{(100-12)} \times 500\right\}$
$=$ Rs. $\left(\frac{100}{88} \times 500\right)$
$=$ Rs. $568.18$
Total CP of the two chairs $=$ Rs. $(416.67+568.18)$
$\quad=$ Rs. $984.85$
Total SP of the two chairs $=$ Rs. $(500 \times 2)$
$\quad=$ Rs. 1000
Since SP $>$ CP, there is a gain in the whole transaction.
Now, gain $=$ Rs. $(1000-984.85)$
$=R s .15 .15$
$\therefore$ Gain percentage $=\left(\frac{\text { gain }}{\text { CP }} \times 100\right) \%$
$=\left(\frac{15.15}{984.85} \times 100\right) \%$
$=1.5 \%$