A shopkeeper loses $7 \%$ by selling a cricket ball for $Rs.\,31.$ For how much should he sell the ball so as to $\operatorname{gain} 5 \% ?$ (in $Rs.$)
$50$
$65$
$35$
None of these
$'A ^{\prime}$ sells an article to $'B ^{\prime}$ at a gain of $20 \%$ and $' B ^{\prime}$ sells it to $'C ^{\prime}$ at a gain of $10 \%$ and $'C ^{\prime}$ sells it to $'D'$ at a gain of $12 \frac{1}{2} \%$. If ${ }^{\prime} D$ ' pays $Rs.\, 29.70$ what did it cost to $'A ^{\prime} ?$ (in $Rs.$)
If the cost price of $20$ articles is equal to the selling price of $15$ articles, find the profit percent?
If profit is $\left(\frac{1}{11}\right)$ th of selling price, what is the profit percent?
A person sells two articles, each for $Rs.\,1040.$ He incurs $20 \%$ loss on the first and $10 \%$ loss on the second. Find out overall percent loss.
Rajesh purchased a mobile phone and a refrigerator for $Rs.\, 12000$ and $Rs.\, 10000$ respectively. She sold the refrigerator at a loss of $12$ percent and mobile phone at a profit of $8$ per cent. What is her overall loss$/$profit?