If the cost price of $20$ tables is equal to the selling price of $25$ tables,find the loss percentage. (in $\%$)

$A$ man buys two chairs for a total cost of $900$. By selling one for $\frac{4}{5}$ of its cost and the other for $\frac{5}{4}$ of its cost,he makes a profit of $90$ on the whole transaction. The cost of the lower priced chair is (in $Rs.$)

Aman buys $5$ laptops and $7$ computers for $Rs. 58500$. He sells the laptops at a profit of $10\%$ and computers at a profit of $16\%$ and his total gain is $Rs. 7110$. What price does he pay for a laptop? (in $Rs.$)

$A$ reduction of $10 \%$ in the price of rice enables a person to obtain $25 \text{ kg}$ more for $Rs. 2250$. Find the reduced price per $\text{kg}$ of the rice (in $Rs.$).

On an article,the profit is $210 \%$ of the cost price. If the cost price increases by $40 \%$ but the selling price remains constant,approximately what percent of the selling price will be the profit?

$A$ shopkeeper mixes $26 \, kg$ of wheat which costs $Rs. 20$ per $kg$ with $30 \, kg$ of wheat which costs $Rs. 36$ per $kg$ and sells the mixture at $Rs. 30$ per $kg$. Find the profit percent. (in $\%$)