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 $kg$?

The ratio of the present ages of $R$ and $S$ is $11:17$. $11$ years ago,the ratio of their ages was $11:20$. What is $R$'s present age (in years)?

Three containers have volumes in the ratio $3:4:5$. They are full of mixtures of milk and water. The mixtures contain milk and water in the ratio of $4:1$,$3:1$,and $5:2$ respectively. The contents of all these three containers are poured into a fourth container. The ratio of milk and water in the fourth container is

What is the fourth proportional to $189, 273$ and $153$?

Two numbers are in the ratio $3: 5$. If each number is increased by $10$,the ratio becomes $5: 7$. The numbers are:

The mean proportional between $64$ and $81$ is