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 $RS.$?

The cost price of an article is $64 \%$ of the marked price. Calculated the gain per cent after allowing a discount of $12 \%$

A shopkeeper purchased a chair marked at $RS.\, 600$ at two successive discounts of $15 \%$ and $20 \% .$ He spent $Rs.\, 28$ on transportation and sold the chair for $Rs.\,545.$ His gain percent was

A shopkeeper sold an item at $10 \%$ loss after giving a discount equal to half the marked price. The cost price of the item is......... of marked price

A man bought $500$ metres of electronic wire at $50$ paise per metre. He sold $50 \%$ of it at a profit of $5 \%$ At what percent should he sell the remainder so as to gain $10 \%$ on the whole transaction?

At what price should a shopkeeper mark a radio that costs him $Rs.\,1200$ in order that he may offer a discount of $20 \%$ on the marked price and still make a profit of $25 \% ? \quad$