$A$ shopkeeper mixes $26 \, kg$ of wheat which costs $Rs. 20$ per $kg$ with $30 \, kg$ of wheat which costs $Rs. 36$ per $kg$ and sells the mixture at $Rs. 30$ per $kg$. Find the profit percent. (in $\%$)

$A$ shopkeeper sells notebooks at the rate of $Rs. 457$ each and earns a commission of $4\%$. He also sells pencil boxes at the rate of $Rs. 80$ each and earns a commission of $20\%$. How much total commission will he earn in two weeks if he sells $10$ notebooks and $6$ pencil boxes a day?

$A$ shopkeeper purchased $245$ pieces of an article at $Rs. 30$ per piece. He spent $Rs. 980$ on transport and $Rs. 1470$ on packing the articles. He sold the articles at the rate of $Rs. 50$ per piece. What is the percent profit earned?

$A$ businessman allows a discount of $10 \%$ on the marked price. What percent above the cost price must he mark his goods to make a profit of $17 \% ?$

$A$ person incurs a $5 \%$ loss by selling a watch for $Rs. 1140$. At what price should the watch be sold to earn a $5 \%$ profit?

$A$ shopkeeper sold a $TV$ set for $Rs. 17940$ with a discount of $8 \%$ and earned a profit of $19.6 \%$. What would have been the percentage of profit earned if no discount was offered (in $\%$)?