Two types of alloys contain gold and silver in the ratio of $7: 22$ and $21: 37.$ In what ratio should these alloys be mixed,so as to have a new alloy in which gold and silver would exist in the ratio $25: 62?$

$A$ $20\, \text{litre}$ mixture of milk and water contains milk and water in the ratio $3:2$. $10\, \text{litres}$ of the mixture is removed and replaced with pure milk,and the operation is repeated once more. At the end of the two removals and replacements,what is the ratio of milk and water in the resultant mixture?

In a mixture of $60\, L$,the ratio of acid and water is $2:1$. If the ratio of acid and water is to be $1:2$,then the amount of water (in $litres$) to be added to the mixture is:

In what proportion must sugar of $Rs. 17$ per $kg$ be mixed with sugar of $Rs. 29$ per $kg$ to make a mixture of $Rs. 20$ per $kg$?

Two vessels contain milk and water in the ratio $3:2$ and $7:3$. Find the ratio in which the contents of the two vessels have to be mixed to get a new mixture in which the ratio of milk and water is $2:1$.

Find the ratio in which rice at ₹ $7.20/kg$ should be mixed with rice at ₹ $5.70/kg$ to produce a mixture worth ₹ $6.30/kg$.