In what ratio must a grocer mix two varieties of tea worth ₹ $60$ a $kg$ and ₹ $65$ a $kg$ so that by selling the mixture at ₹ $68.20$ a $kg$ he may gain $10 \%$?

Mira's expenditure and savings are in the ratio $3: 2$. Her income increases by $10 \%$. Her expenditure also increases by $12 \%$. By how many $\%$ does her saving increase?

In what proportion must a grocer mix sugar at ₹ $12$ per $kg$ and ₹ $7$ per $kg$ so as to make a mixture worth ₹ $8$ per $kg$?

$A$ person has a chemical costing $Rs. 25$ per $litre$. In what ratio should water be mixed in the chemical so that by selling the mixture at $Rs. 20$ per $litre$,he may get a profit of $25\%$?

$20$ litres of a mixture contains $20 \%$ alcohol and the rest is water. If $4$ litres of water are added to it,what will be the percentage of alcohol in the new mixture?

Three bottles of equal capacity contain mixtures of milk and water in the ratios $2:5$,$3:4$,and $4:5$ respectively. These three bottles are emptied into a large bottle. What will be the ratio of milk and water respectively in the large bottle?