In a mixture of $60 \ L$,the ratio of milk and water is $2:1$. What quantity of water (in $L$) should be added so that the ratio becomes $1:3$?

When wheat is ₹ $13$ per $kg$,$75$ men can be fed for $15$ $days$ at a certain cost. How many men can be fed for $45$ $days$ at the same cost,when wheat is ₹ $1$ per $kg$?

When $30$ percent of one number is subtracted from another number,the second number reduces to its four-fifth. What is the ratio between the first and the second number respectively?

An alloy of copper and zinc is taken in the ratio $1: 2$,and another alloy of the same metals is taken in the ratio of $2: 3$. How many parts of the two alloys must be taken to obtain a new alloy consisting of copper and zinc that are in the ratio $3: 5$?

The ratio of three numbers is $2: 3: 5$. If the sum of the three numbers is $275$,then what is the largest among the three numbers?

The ratio of the sum of two numbers and their difference is $5:1$. The ratio of the greater number to the smaller number is