A man bought apples at the rate of 6 for $Rs.\,20$ and sold them at $4$ for $Rs.\, 16.$ His estimated profit $\%$ is

While selling a watch, a shopkeeper gives a discount of $15 \% .$ If he gives a discount of $20 \%,$ he earns $Rs.\, 51$ less as profit. What is the original price of the watch? (in $Rs$)

If the cost price of $20$ articles is equal to the selling price of $15$ articles, find the profit percent?

A man sells two article for $Rs.\,5000$ each neither losing nor gaining in the deal. If he sold one of them at a gain of $25 \%,$ the other article is sold at a loss of.......$\%$

A manufacturer undertakes to supply $2000$ pieces of a particular component at $Rs.\, 25$ per piece. According to his estimates, even if $5 \%$ fail to pass the quality tests, then he will make a profit of $25 \% .$ However, as it turned out, $50 \%$ of the components were rejected. What is the loss to the manufacturer ? (in $Rs.$)

By selling $25$ $metres$ of cloth a trader gains the selling price of $5$ $metres$ of cloth. The gain of the trader in $\%$ is