$A$ vendor started selling vegetables at $Rs. 10$ per $kg$,but could not find buyers at this rate. So,he reduced the price to $Rs. 8.10$ per $kg$,but uses a faulty weight of $900\, g$ for $1\, kg$. Find the percent change in the actual price or loss. (in $\%$)

$A$ man purchases some oranges at the rate of $3$ for $₹ 40$ and the same quantity at $5$ for $₹ 60$. If he sells all the oranges at the rate of $3$ for $₹ 50$,find his gain or loss percent (to the nearest integer).

Find $SP$ when $CP = Rs. 56.25$ and $\text{Gain} = 20\%$?

An electric pump was sold at a profit of $15 \%$. Had it been sold for $Rs. 600$, the profit would have been $20 \%$. What was the former selling price in $Rs.$?

$A$ man bought apples at the rate of $8$ for $Rs. 34$ and sold them at the rate of $12$ for $Rs. 57$. How many apples should be sold to earn a net profit of $Rs. 45$?

Ajit calculates his profit percentage on the selling price,whereas Rohit calculates his on the cost price. They find that the difference between their profits is $Rs. 100$. If the selling price for both of them is the same and both of them get a $25\%$ profit,find their selling price (in $Rs.$).