$A$ sugar solution of $3$ $litre$ contains $60 \%$ sugar. One litre of water is added to this solution. Then the percentage of sugar in the new solution is (in $\%$)

$A$ shopkeeper has $50 \ kg$ of rice,a part of which he sells at $10 \%$ profit and the rest at $5 \%$ loss. He gains $7 \%$ on the whole. What is the quantity sold at $10 \%$ gain?

$A$ sum of ₹ $390$ was divided among $450$ boys and girls. Each girl gets $50$ paise and each boy gets one rupee. How many girls are there among them?

In what proportion must water be added to spirit to gain $20 \%$ by selling it at the cost price (in $:5$)?

In a $729 \ L$ mixture of milk and water,the ratio of milk to water is $7:2.$ To get a new mixture containing milk and water in the ratio $7:3,$ the amount of water to be added is (in $L$)

$A$ sum of $Rs. 41$ was divided among $50$ children. Each boy gets $90$ paise and each girl $65$ paise. The number of boys is?