A cup of milk contains $3$ parts pure milk and one part of water. How much of the mixture must be part of water. How much of the mixture must be withdrawn and substituted by water in order that the resulting mixture may be half milk and half water.

A jar full of whisky contains $40\%$ of alcohol. A part of this whisky is replaced by another containing $19\%$ alcohol and now the percentage of alcohol was found to be $26$. The quantity of whisky replaced is:

Some amount out of $₹7000$ was lent at$6\%$ p.a. and the remaining at$4\%$ p.a. If the total simple interest from both the parts in $5$years was $₹1600$, the sum lent at $6\%$ p.a. was:

A lump of two metals weighing $18$grams is worth $Rs.74$ but if their weights are interchanged, it would be worth $Rs.60.10$. If the price of one metal be $Rs.7.20$ per gram, find the weight of the other metal in the mixture?

There are two vessels, one containing $12$ litres of water, the other $6$ litres of wine. If a litre is taken out of each and poured into the other, and if this is repeated four times, find how much wine will be in container one.

Two jars containing respectively $3$ and $5$ litres are filled with mixtures of alcohol and water. In the smaller jar $25\%$ of the mixture is alcohol, in the larger $25\%$ of the mixture is water. The jars are emptied into a $9$ litre cask, which is filled up with water. Find the percentage of alcohol in the cask.