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

If a radio is purchased for $Rs. 490$ and sold for $Rs. 465.50$,find the $\text{loss} \%$. (in $\%$)

$A$ man bought $15$ mangoes for a rupee. How many mangoes were sold for a rupee so that there is a loss of $25 \% ?$

$A$ shopkeeper sells notebooks at the rate of $Rs.\, 45$ 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? (in $Rs.$)

$A$ sells a bicycle to $B$ at a profit of $20 \%.$ $B$ sells it to $C$ at a profit of $25 \%.$ If $C$ pays $Rs. 225$ for it,the cost price of the bicycle for $A$ is (in $Rs.$)

The price of a $TV$ is $Rs. 10,000$. If successive discounts of $15\%$,$10\%$,and $5\%$ are allowed,then at what price does a customer buy it in $Rs.$?