A sells an article to $B$ at a gain of $20 \%$ and $B$ sells it to $C$ at a gain of $10 \%$ and $C$ sells it to $D$ at a gain of $12 \frac{1}{2} \% .$ If $D$ pays $Rs.\, 29.70,$ then $A$ purchased the article for (in $Rs.$)

Profit earned by an organization is distributed among officers and clerks in the ratio of $5: 3 .$ If the number of officers is $45$ and the number of clerks is $80$ and the amount received by each officer is $Rs.\,25,000,$ what was the total amount of profit earned? (in $Rs.$.......$lakhs$)

An electric pump was sold at a profit of $15 \% .$ Had it been sold.for $Rs.\, 600$ , the profit would have been $20 \% .$ The former selling price is in $Rs.?$

By selling $25$ $metres$ of cloth a trader gains the selling price of $5$ $metres$ of cloth. The gain of the trader in $\%$ is

A man buys an article for $Rs.\;27.50$ and sells it for $Rs.\, 28.60.$ Find the gain percent?

Nutan bought $30$ dozens of oranges for her juice stall in the school fair. She paid $Rs.\, 8$ per dozen of oranges. She also had to pay $Rs\, 500$ as the stall fee to the school authorities. She calculated that each glass'of juice would need $3$ oranges. How much should she charge per glass of juice so as to make $20 \%$ profit in $Rs?$