$A$ trader mixes $26 \text{ kg}$ of rice at $Rs. 20$ per $\text{kg}$ with $30 \text{ kg}$ of rice of another variety at $Rs. 36$ per $\text{kg}$ and sells the mixture at $Rs. 30$ per $\text{kg}$. His profit percent is:

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

$A$ shopkeeper gains the cost of $8$ metres of thread by selling $40$ metres of thread. Find his gain percent.

At a cost of $60$ paise per article,Sarika produces $750$ articles. She sets the selling price such that if only $600$ articles are sold,she would have made a profit of $40 \%$ on the total outlay. However,$120$ articles got spoilt and she was able to sell $630$ articles at this price. Find her actual profit or loss percent as a percentage of the total outlay,assuming that the unsold articles are useless.

The difference between a discount of $35 \%$ and two successive discounts of $20 \%$ on a certain bill was $Rs$ $22$. Find the amount of the bill in $Rs$.

An article is sold at a profit of $20 \%$. If both the cost price and selling price are $Rs. 150$ less,the profit would be $5 \%$ more. Find the cost price.