If selling price is doubled, profit triples. Find the profit percent.

The market price of an article is $Rs.$ $100 .$ If the article is sold at a discount of $10 \%,$ then $35 \%$ profit is realised. How much loss or profit will be made if it is sold for $Rs.\, 30$ less than market price?

The labelled price of a cupboard is $Rs$ $6500 .$ The shopkeeper sold it by giving $5 \%$ discount on the labelled price and earned a profit of $15 \% .$ What approximately is the cost price of the cupboard? (in $Rs.$)

If a vendor sells a coconut at $Rs.\, 14.4$ he makes $10 \%$ Ioss. If he wants to make $25 \%$ profit, there at what price (in $Rs.$) should he sell?

Two discounts of $40 \%$ and $20 \%$ equal to a single discount of $\%$?

A $TV$ set is being sold for $Rs.$ $x$ in Chandigarh. A dealer went to Dellini and bought the $TV$ at $20 \%$ discount (from the price of Chandigarh). He spent $Rs.\, 600$ on transport. Thus he sold the set in Chandigarh for $Rs.$ $x$ making $14 \frac{2}{7} \%$ profit. What was $x$ in $Rs.?$