A reduction of $21 \%$ in the price of an item enables a person to buy $3\, Kg$ more for $Rs.\,100.$ The reduced price of the item per $Kg$ is (in $Rs.$)

On a $Rs.\,10,000$ payment order, a person has a choice between three successive discounts of $10 \%, 10 \%$ and $30 \%$ and three successive discounts of $40 \%, 5 \%$ and $5 \% .$ By choosing the better offer, he can save in $Rs.$?

An article is sold at a certain fixed price. By selling it at $\frac{2}{3}$ of that price, one loses $10 \%$. The gain percent on selling it at the original price is

A dealer sold two types of goods for $Rs. 10,000$ each. On one of them, he lost $20 \%$ and on the other he gained $20 \%$. His gain or loss per cent in the entire transaction was

Some articles were bought at $6$ articles for $Rs.\,5$ and sold at $5$ articles for $Rs.$ $6 .$ Gain percent is

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