Sanjay purchased a chair marked at $Rs.\, 800$ at $2$ successive discount of $10 \%$ and $15 \%$ respectively. He spent $Rs.\, 28$ on transportation and sold the chair for $Rs.$ $800 .$ How much is his gain percentage?

If an item is sold for $Rs.\, 924$ then there is a profit of $10 \%$ then what is the cost price in $\%$?

A trader purchase a wrist watch and a pendulum for $Rs.$ $390.$ He sells them making a profit of $10 \%$ on the watch and $15 \%$ on the pendulum. He earns a profit of $Rs$. $51.50 .$ The difference between the original prices of the pendulum and the watch is equal to? (in $Rs.$)

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 amount of commission will he earn in two weeks if he sells $10$ notebooks and $6$ pencil boxes a day?

Tarun bought a $TV$ with $20 \%$ discount on the labelled price. Had he bought it with $25 \%$ discount, he would have saved $Rs.\,500.$ At what price did he buy the $TV?$

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 $Rs$)