When a book is sold at its Marked Price it gives a profit of $40 \% .$ What $\%$ will happen if it is sold at half the marked Price?

The price of $12$ chair and $8$ table is Rs. $676 .$ What is the price of $21$ chair and $14$ table in $Rs.$?

A trader mixes three varieties of groundnuts costing $Rs. \,50, Rs.\, 20$ and $Rs.\, 30$ per $k g$ in the ratio $2: 4: 3$ in terms of weight and sells the mixture at $Rs.\, 33$ per $kg .$ What percentage of profit does he make?

Mohit purchased $40\, kg$ of wheat at $Rs.\,12 .50$ per $kg$ and $25\, kg$ of wheat at $Rs.\,15.10$ per $kg.$ He mixed the two qualities of wheat for selling. At what rate should it be sold to gain $10 \% ?$ (in $Rs.)$

The profit earned by selling an article for $Rs. 832$ is equal to the loss incurred when the same article is sold for $Rs. 448.$ What should be the selling price for making $50\%$ profit? (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?