$A$ shopkeeper gains the cost of $8$ metres of thread by selling $40$ metres of thread. Find his gain percent.

In a certain store,the profit is $320 \%$ of the cost. If the cost increases by $25 \%$ but the selling price remains constant,approximately what percentage of the selling price is the profit?

$A$ man purchased $120$ reams of paper at $Rs. 80$ per ream. He spent $Rs. 280$ on transportation,paid octroi at the rate of $40$ paise per ream,and paid $Rs. 72$ to a porter. In order to gain $8\%$ profit,he must sell each ream of paper for (in $Rs.$):

If a company sells a car with a marked price of $Rs. 272000$ and gives a discount of $4\%$ on $Rs. 200000$ and $2.5\%$ on the remaining amount of $Rs. 72000$,then the actual price charged by the company for the car is (in $Rs.$)

$A$ trader mixes $26 \text{ kg}$ of rice at $Rs. 20$ per $\text{kg}$ with $30 \text{ kg}$ of rice of another variety at $Rs. 36$ per $\text{kg}$ and sells the mixture at $Rs. 30$ per $\text{kg}$. His profit percent is:

Albert buys $4$ horses and $9$ cows for $Rs. 13400$. If he sells the horses at $10 \%$ profit and the cows at $20 \%$ profit,then he earns a total profit of $Rs. 1880$. The cost price of a horse is (in $Rs.$)