Oil equal to $20 \%$ of the weight of ground nut is extracted in a mill. The matter left after extraction is sold as cattle feed at the rate of $Rs.\, 12.5$ per $kg$. The ground nuts are bought at $Rs.$ $20$ per $kg.$ the processing cost is $Rs.\, 5$ per $kg$. At what price $(Rs.$ per $kg$ ) should the oil be sold to earn $20 \%$ profit on total costs (Total cost $=$ cost of groundnuts and processing costs)?

If $5 \%$ more is gained by selling an article for $Rs.\, 350$ than by selling it for $Rs$ $340,$ the cost of the article is......$\%$

Mohan buys a watch for $Rs.\,350$ and sells it for $Rs.\,392.$ Find out his percentage of profit.

Profit earned by selling an article of $Rs.\, 1630$ is same as the loss incurred by selling the article for $Rs.$ $1320 .$ What is the $CP$ in $Rs$?

A dealer sold two types of goods for $Rs. 10,000$ each. On one of them, he lost $20 \%$ and on the other he gained $20 \%$. His gain or loss per cent in the entire transaction was

If a radio is purchased for $Rs.\, 490$ and sold for $Rs.$ $465.50 .$ Find the $\operatorname{loss} \% ?$