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 sold a horse to $B$ for $Rs.\, 4800$ by losing $20 \%$. $B$ sells it to $C$ at a price which would have given $A$ a profit of $15 \% .$ $B's$ gain is (in $Rs.$)

A shopkeeper sells goods at $10 \%$ loss on cost price, but uses $20 \%$ less weight. What is his profit or loss percentage?

A man sold two cows at $Rs. \,1995$ each. On one he lost $10 \%$ and on the other he gained $10 \% .$ What his gain or loss percent?

A shopkeeper sells notebooks at the rate of $Rs.\, 45$ each and earns a commission of $4 \% .$ He also sells pencil box at the rate of $Rs.\, 80$ each and earns a commission of $20 \% .$ How much amount of commission will he earn in two weeks if he sells $10$ notebooks and $6$ pencil boxes a day? (in $Rs.$)

A vendor buys bananas at $9$ for $Rs. 8$ and sells at 8 for $Rs. 9.$ What will be the profit or loss (in $\%$)?