Find the number which,when subtracted from the terms of the ratio $12: 17$,makes it equal to the ratio $2: 3$.

In a family,the ratio of expenses to savings is $5:3$. If the expenses increase by $60\%$ and the income increases by $25\%$,the savings decrease by $Rs. 3500$. Find the increased income (in $Rs.$) of the family.

Three numbers are in the ratio $5:6:7$. If the product of the numbers is $5670$,then the greatest number is:

$A$ box contains ₹ $56$ in the form of coins of one-rupee,$50-paise$ and $25-paise$. The number of $50-paise$ coins is double the number of $25-paise$ coins and four times the number of one-rupee coins. How many $50-paise$ coins are there in the box?

$A$ box contains $210$ coins of denominations $Rs. 1$ and $50$ paise. The ratio of their respective values is $13: 11$. The number of $Rs. 1$ coins is:

The ratio of the number of boys to girls in an institution is $6:5$. If there are $192$ boys in total,find the total number of students in the institution.