On the entire Earth,the ratio between land and water is $1:2$,and in the Northern Hemisphere,this ratio is $2:3$. What will be the ratio of land to water in the Southern Hemisphere?

What will be the inverse ratio of $17: 19$?

$A$ man spends $Rs. 2310$ on an average during the first $8$ months from his income. During the next $4$ months,he spends $Rs. 1800$ on an average from his income,but he had taken a loan of $Rs. 1680$ apart from his income to meet his expenses. If he spent all that he had,what is the ratio of his average income to his average expenditure?

If $x: y = 2: 1,$ then $(x^{2} - y^{2}) : (x^{2} + y^{2})$ is

The ratio of the number of boys and girls in a school is $3:2$. If $20\%$ of the boys and $25\%$ of the girls are scholarship holders,what percentage of the students does not get the scholarship?

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 $kg$?