How much water should be added to $14$ litres of milk worth ₹ $5.40$ a litre so that the value of the mixture may be ₹ $4.20$ a litre? (in litres)

Rama mixes $20 \%$ of kerosene to his petrol and then he sells the whole mixture at the price of petrol. If the cost price of the kerosene is $40 \%$ of the $CP$ of petrol,what is the net profit percentage (in $\%$)?

Two alloys contain tin and iron in the ratio of $1:2$ and $2:3$. If the two alloys are mixed in the proportion of $3:4$ respectively (by weight),the ratio of tin and iron in the newly formed alloy is:

How many $kg$ of sugar costing ₹ $5.50$ per $kg$ must be mixed with $60 \ kg$ of sugar costing ₹ $4.80$ per $kg$ so that the mixture is worth ₹ $5.25$ per $kg$?

$A$ trader has $50 \text{ kg}$ of pulses,part of which he sells at $8 \%$ profit and the rest at $18 \%$ profit. He gains $14 \%$ on the whole. What is the quantity sold at $18 \%$ profit? (in $\text{kg}$)

In two types of brass,the ratios of Copper to Zinc are $8:3$ and $15:7$ respectively. If the two types of brass are melted and mixed in the ratio $5:2$,a new type of brass is obtained. The ratio of Copper to Zinc in this new type of brass is: