$A$ man sells a scooter to his friend at $10\%$ loss. If the friend sells it for $₹ 54000$ and gains $20\%$,find out the original cost price of the scooter. (in $₹$)

Nutan pays $Rs. 2140$ for $3$ calculators and $4$ pens,while she pays $Rs. 1355$ for $1$ additional calculator and $5$ pens. What is the cost of a calculator in $Rs.$?

If profit is $\left(\frac{1}{11}\right)$ of the selling price,what is the profit percent?

$A$ sells a suitcase to $B$ at $10\%$ profit. $B$ sells it to $C$ at $30\%$ profit. If $C$ pays $₹ 2,860$ for it,then the price at which $A$ bought it is (in $₹$):

$A$ shopkeeper bought $30 \text{ kg}$ of wheat at the rate of $₹ 45$ per $\text{kg}$. He sold $40\%$ of the total quantity at the rate of $₹ 50$ per $\text{kg}$. Approximately,at what price per $\text{kg}$ should he sell the remaining quantity to make $25\%$ overall profit? (in $₹$)

The list price of a shirt is $Rs. 440$ and a customer pays $Rs. 396$ for it. The discount rate is.......$\%$