The sum of two numbers is three times their difference. What is the ratio of the two numbers?

$A$'s income is ₹ $140$ more than $B$'s income and $C$'s income is ₹ $80$ more than $D$'s. If the ratio of $A$'s and $C$'s incomes is $2:3$ and the ratio of $B$'s and $D$'s incomes is $1:2$,then the incomes of $A, B, C$ and $D$ are respectively (in ₹):

In a college, $150$ students of $MBA$ are enrolled. The ratio of boys to girls is $7:8$. There are three disciplines: Marketing, $HR$, and Finance. In Marketing, $50\%$ of the girls and $40\%$ of the boys are enrolled. In $HR$, $30\%$ of the girls and $30\%$ of the boys are enrolled. In Finance, $20\%$ of the girls and $30\%$ of the boys are enrolled. $7$ boys and $9$ girls are in both $HR$ and Marketing. $6$ boys and $7$ girls are in both $HR$ and Finance. $5$ boys and $8$ girls are in both Marketing and Finance. $2$ boys and $3$ girls are in all three disciplines. Find the ratio of the number of boys in both Marketing and Finance to the number of girls only in Finance.

$A$ 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?

Find a fourth proportional to the numbers $60, 48, 30$.

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