If the ratio of the cost price and selling price of an article is $20: 21,$ then what will be the profit percent?
$5$
$4.5$
$6$
$7.5$
A sells an article to $B$ at a profit of $20 \%$ and $B$ sells it to $C$ at a loss of $10 \% .$ If $C$ pays $Rs.\,540$ for it, at what price did A buy?
Arun buys one kilogram of apples for $Rs.\, 120$ and sells it to Swati gaining $25 \%$. Swati sells it to Divya who again sells it for $Rs.\, 198,$ making a profit of $10 \%$. What is the profit percentage made by Swati?
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 $Rs.$)
A man purchased some eggs at $3$ for $Rs.\, 5$ and sold them at $5$ for $Rs.\, 12 .$ Thus, he gained $Rs.\, 143$ in all. The number of eggs he bought is
A shopkeeper marks his goods at $40 \%$ above their cost price. He is able to sell $\frac{3}{4}$ th of his goods at this price, and the remaining at $40 \%$ discount. Assuming that the shopkeeper is able to sell the goods he buys, find his loss or gain as $\%$ of the whole transaction.