A discountof $40 \%$ on the marked price of atrouser enables Ajit to purchase a shirt also which costs him $Rs.\,320.$ How much did Ajit payfor the trouser? (in $Rs.$)

The profit earned by selling an article for $Rs.\, 900$ is double the loss incurred when the same article is sold for $Rs.$ $450 .$ At what price should the article be sold to make $25 \%$ profit in $Rs.$?

Nutan pays $Rs.\, 2140$ for $3$ calculator and $4$ Pen while he pay $Rs.\, 1355$ for an additional calculator and $5$ Pen. Then what he paid for Calculator only in $RS.$?

A merchant buys $4000\, kg$ of wheat, one$-$fifth of which he sells at a gain of $5$ per cent, one$-$fourth at a gain of $10 \%$, one-half at a gain of $12$ percent, and the remainder at a gain of $16$ percent. If he had sold the whole at a gain of $11$ percent, he would have made $Rs.\, 72.80$ more. What was the cost price of the crop per kg? (in $Rs.$)

Three successive discounts of $10 \%, 12 \%$ and $15 \%$ will amount to a single discount of in $\%$?

By selling $100$ oranges, a vendor gains the selling price of $20$ oranges. He gain percent is