Sarita sells a phone at a profit of $20 \%$. If she had bought it at $20 \%$ less and sold it for $Rs. 180$ less, she would have gained $25 \%$. Find the cost price of the phone in $Rs.$

The marked price of a clock is $Rs. 3200$. It is sold at $Rs. 2448$ after two successive discounts. If the first discount is $10 \%$,then the second discount is.........$\%$

$A$ man buys $100 \, kg$ of sugar for $Rs. \, 2400$. He sold $1/4$th of the stock at a loss of $5 \%$. At what per cent profit should he sell the remaining stock so as to make an overall profit of $20 \%$ on the whole transaction? (in $\%$)

$A$ fruit-seller buys some oranges and by selling $40 \%$ of them he realizes the cost price of all the oranges. As the oranges begin to grow over-ripe,he reduces the price and sells $80 \%$ of the remaining oranges at half the previous rate of profit. The rest of the oranges being rotten are thrown away. The overall percentage of profit is (in $\%$)

$A$ man buys an article for $10 \%$ less than its value and sells it for $10 \%$ more than its value. His gain or loss percent is

$A$ cab driver makes a profit of $20 \%$ on every trip when he carries $3$ passengers and the price of petrol is $Rs. 30$ a litre. Find the percentage profit for the same journey if he goes with four passengers per trip and the price of petrol reduces to $Rs. 24$ a litre? (in $\%$)
(Assume that revenue per passenger is the same in both the cases.)