Find the third proportional to the numbers $4$ and $42$.

$A$ person distributes his pens among four friends $A, B, C$ and $D$ in the ratio $\frac{1}{3}: \frac{1}{4}: \frac{1}{5}: \frac{1}{6}$. What is the minimum number of pens that the person should have?

If $3 A = 5 B$ and $2 B = 3 C$,then $A : C$ is

$A$ box of sweets was distributed between $A$ and $B$ in the ratio $3:4$. If $A$ got $36$ sweets,what was the total number of sweets?

Three brothers divided ₹ $1620$ among themselves in such a way that the share of the second brother is equal to $\frac{5}{13}$ of the share of the other two combined. What is the share of the second brother?

$A$ 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?