A pair of article, was bought for $Rs.\, 37.40$ at a discount of $15 \% .$ What must be the marked price of each of the articles?

A dealer buys a table listed at $Rs.\, 600$ and gets successive discount of $10 \%$ and $20 \% .$ What is his profit or loss percent if he sells at $Rs.$ $540 ?$

A shopkeeper sells notebooks at the rate of $Rs.\,457$ 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 amount of commission will he earn in two weeks if he sells $10$ notebooks and $6$ pencil boxes a day?

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 person sold a horse at a gain of $15 \% .$ Had he bought it for $25 \%$ less and sold it for $Rs.\,60$ less, he would have made a profit of $32 \% .$ The cost price of the horse was (in $Rs.$)

If the discount of $10 \%$ is given on the marked price of a radio, the gain is $20 \%$. If the discount is increased to $20 \%,$ the gain is......$\%$