Question

Mr Mehta purchased a video for Rs 20000 and a television for Rs 30000. On the video he lost 5% and on the television he gained 8%. Find his total gain or loss per cent.

Answer 1

Mr. Mehta purchased a video at the cost of Rs. 20000.
Mr. Mehta purchased a television at the cost of Rs. 30000.
Total cost = Rs. (20000 + 30000) = Rs. 50000

He lost 5% on the video.

$$\begin{gathered} \mathrm{SP}=\frac{(100-L\mathrm{oss}\%)}{100}\times \mathrm{CP} \\ =\frac{100-5}{100}\times 20000 \\ =\frac{95}{100}\times 20000 \\ =\mathrm{Rs}.19000 \end{gathered}$$

He gained 8% on the television.

$$\begin{gathered} \mathrm{SP}=\frac{(100+G\mathrm{ain}\%)}{100}\times \mathrm{CP} \\ =\frac{100+8}{100}\times 30000 \\ =\frac{108}{100}\times 30000 \\ =\mathrm{Rs}.32400 \end{gathered}$$

Total SP = $\mathrm{Rs}.(190000+32400)=\mathrm{Rs}.51400$

Total CP = Rs. 50000
Total Gain = SP - CP = $\mathrm{Rs}.(51400-50000)=\mathrm{Rs}.1400$
$$\begin{gathered} \mathrm{Gain}\%=\left(\frac{\mathrm{Gain}}{\mathrm{CP}}\times 100\right)\% \\ =\left(\frac{1400}{50000}\times 100\right)\% \\ =2.8\% \end{gathered}$$