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 $Rs.)$

Sonal buys mangoes at the rate of $3 \,kgs$ for $Rs$. $21$ and sells them at $5$ $kgs$ for $Rs.$ $50 .$ To earn a profit of $Rs.\,102,$ he must sell how many mangoes in $kgs$?

Two toys are sold at $Rs.\,504$ each. One toy brings the dealer a gain of $12 \%$ and the other a loss of $4 \%$. The gain or loss per cent by selling both the toys is

An article which is marked at $Rs.\, 975$ is sold for $Rs.\, 897$. The $\%$ discount is?

Rita buys an article for $Rs.$ $9600.$ She sold it at $12 \%$ loss and get some money and from that money she again buys an article and this time she got $12 \%$ profit. What was profit or loss she got form this transaction in $Rs.$?

If the selling price of $40$ articles is equal to the cost price of $50$ articles, the loss or gain percent is