Question

A shopkeeper buys some pens at 8 per pen and the same number of pencils at 36 per pencil. He
makes a 10% profit on the pens and a 20% profit on the pencils. At the end of day, all the pens and
pencils are sold out and he makes a profit of 320. Find the number of pens purchased.​

Answer 1

Answer:

8X × 10%) + (36X × 20%) = 320

\begin{gathered} \frac{8x \times 10}{100} + \frac{36x \times 20}{100} = 320 \\ \\ \frac{80x + 720x}{100} = 320 \\ \\ \frac{800x}{100} = 320 \\ \\ 8x = 320 \\ \\ x = \frac{320}{8} \\ \\ x = 40\end{gathered}1008x×10+10036x×20=32010080x+720x=320100800x=3208x=320x=8320x=40