Due to a $20\%$ rise in the price of sugar,a bachelor is able to buy $1.5\, kg$ less for $Rs.\, 135$. What is the increased price of sugar per $kg$ in $Rs.$?

$A$ 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 $Rs.$)

The ratio between the selling price and the cost price of an article is $7:5$. What is the ratio between the profit and the cost price of that article?

The marked price of a watch was $Rs. 720$. $A$ man bought the same for $Rs. 550.80$ after getting two successive discounts,the first being $10\%$. What was the second discount rate? (in $\%$)

Paras Health Care made $3000$ strips of vitamin tablets at a cost of $Rs. 4800$. The company gave away $1000$ strips of tablets to doctors as free samples. $A$ discount of $25\%$ is given on the printed price. Find the ratio of profit in $Rs.$ if the price is raised from $Rs. 3.25$ to $Rs. 4.25$ per strip and if at the latter price,samples to doctors were done away with.

$A$ fan costing $Rs. 1200$ is being sold for $Rs. 1500$. What is the profit percent?