Find the gain or loss per cent when:

(i) $\mathrm{CP}=$ Rs. 620

$\mathrm{SP}=$ Rs. 713

Since $S P>C P$, there is a gain.

Gain $=713-620=$ Rs. 93

Gain percentage $=\left(\frac{\text { gain }}{\mathrm{CP}} \times 100\right) \%$

$=\left(\frac{93}{620} \times 100\right) \%$

$=15 \%$

(ii) $\mathrm{CP}=\mathrm{Rs} 675$

$\mathrm{SP}=\mathrm{Rs} 630$

Since SP $<\mathrm{CP}$, there is a loss. Loss

$=675-630=$ Rs. 45 Loss percentage $=\left(\frac{\text { Loss }}{\mathrm{CP}} \times 100\right) \%$

Loss $=675-630=$ Rs. 45

Loss percentage $=\left(\frac{\text { Loss }}{\text { CP }} \times 100\right) \%$

$=\left(\frac{45}{675} \times 100\right) \%$

$=6 \frac{2}{3} \%$

(ii) $\mathrm{CP}=$ Rs. 345

$\mathrm{SP}=$ Rs. $372.60$

Since SP $>\mathrm{CP}$, there is a gain.

Gain $=372.60-345=$ Rs. $27.6$

Gain percentage $=\left(\frac{\text { gain }}{\mathrm{CP}} \times 100\right) \%$

Gain $=372.60-345=$ Rs. $27.6$

Gain percentage $=\left(\frac{\text { gain }}{\mathrm{CP}} \times 100\right) \%$

$=\left(\frac{27.6}{345} \times 100\right) \%$

$=\left(\frac{2760}{345}\right) \%$

$=8 \%$

(iv) $\mathrm{CP}=\mathrm{Rs} 80$

$\mathrm{SP}=\mathrm{Rs} 76.80$

Since SP $<\mathrm{CP}$, there is a loss.

Loss $=80-76.80=$ Rs. $3.2$

Loss percentage $=\left(\frac{\text { loss }}{\mathrm{CP}} \times 100\right) \%$

Loss $=80-76.80=$ Rs. $3.2$

Loss percentage $=\left(\frac{\text { loss }}{\mathrm{CP}} \times 100\right) \%$

$=\left(\frac{3.2}{80} \times 100\right) \%$

$=\left(\frac{32}{80} \times 100\right) \%$

$=4 \%$