The value of $k$ that must be added to $7, 16, 43,$ and $79$ so that they are in proportion is

If $A: B = 7: 5$ and $B: C = 9: 11,$ then $A: B: C$ is equal to

If $50$ fewer candidates had applied and $25$ fewer had been selected,the ratio of selected to unselected candidates would have been $9:4$. How many candidates had applied if the initial ratio of selected to unselected candidates was $2:1$?

The price of a diamond is directly proportional to the square of its weight. $A$ man accidentally broke the diamond into three pieces in the ratio of $3:5:7$ and thus lost ₹ $42600$. What was the original price (in ₹) of the diamond?

If $0.75 : x :: 5 : 8,$ then $x$ is equal to

In a college,$150$ students of $MBA$ are enrolled. The ratio of boys to girls is $7:8$. There are three disciplines in the college: Marketing,$HR$,and Finance. In the Marketing discipline,there are $50\%$ of the total girls and $40\%$ of the total boys. In the $HR$ discipline,there are $30\%$ of the total girls and $30\%$ of the total boys. In the Finance discipline,there are $20\%$ of the total girls and $30\%$ of the total boys. $7$ 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 enrolled in all three disciplines. What is the ratio of boys to girls only in the Marketing discipline?