When $X$ is subtracted from the numbers $9, 15$ and $27$,the remainders are in continued proportion. What is the value of $X$?

$A$ 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?

The fourth proportional to $5, 8, 15$ is

Find the mean proportional between $9$ and $64$.

Four years ago,the father's age was three times the age of his son. The total of the ages of the father and the son after four years will be $64$ years. What is the father's age at present (in years)?

If Rs. $872$ is divided into three parts,proportional to $\frac{1}{2}: \frac{2}{3}: \frac{3}{4},$ then the first part is