On a certain item,the profit is $150 \%$. If the cost price increases by $25 \%$,what will be the new profit margin (in $\%$)?

$A$ fruit seller sells mangoes at the rate of $Rs. 9$ per $kg$ and thereby loses $20\%$. At what price per $kg$ should he have sold them to make a profit of $5\%$? (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 $Rs.$)

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

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

Mr. Verma sold his scooter for $Rs. 10500$ at a gain of $5 \%$. Find out the cost price of the scooter (in $Rs.$).