Find the value of $x$ in the following proportion: $27: 72 :: x: 8$

Before a war,the ratio of tanks to planes in an army was $5:3$. During the war,$1000$ tanks were destroyed and $800$ planes were destroyed. The ratio of tanks to planes became $2:1$. What is the number of tanks after the war?

The ratio of two numbers is $3:4$ and their sum is $420$. The greater of the two numbers is

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 $kg$?

Present ages of $X$ and $Y$ are in the ratio $5: 6$ respectively. Seven years hence,this ratio will become $6: 7$ respectively. What is $X$'s present age in years?

Two numbers are in the ratio $1: 2$. If $7$ is added to both,the ratio changes to $3: 5$. The greatest number is: