A man sells each of his $2$ articles for $Rs.$ $99.$ On one he gains $10 \%$ and on the other he incurred a loss of $1 \%$ in the entire transaction. What is his total gain in $\%$?

Arun purchased $30\, kg$ of wheat at the rate of $Rs.\,11.50$ per $kg$ and $20\, kg$ of wheat at the rate of $Rs.\,14.25$ per $kg$. He mixed the two and sold the mixture. Approximately at what price per $kg$ should he sell the mixture to make $30 \%$ profit? (in $Rs.$)

A shopkeeper expects a gain of $22 \frac{1}{2} \%$ on his cost price. If in a week, his sale was of $Rs. \,392$ what was his profit? (in $Rs$)

If selling price is doubled, the profit triples. Find the profit percent

A dealer fixed the price of an article $40 \%$ above the cost of production. While selling it he allows a discount of $20 \%$ and makes a profit of $Rs.\, 48$. The cost of production (in $Rs.$) of the article is