The ratio of boys and girls in a school is $9:5$. If the total number of students in the school is $1050$,then the number of boys is

$Rs. 366$ are divided among $A, B$ and $C$ such that $A$ gets $\frac{1}{2}$ as much as $B$ and $C$ together,and $B$ gets $\frac{2}{3}$ as much as $A$ and $C$ together. What is the share of $A$ (in $Rs.$)?

$A$ 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?

What is the fourth proportional to $189, 273$ and $153$?

$P$ varies inversely with the product of $Q$ and $R$. When $Q = 6$ and $R = 12$,$P = 75$. When $Q = 5$ and $R = 10$,what is the value of $P$?

The ratio of the ages of a man and his wife is $4:3$. After $4$ years,this ratio will be $9:7$. If at the time of marriage,the ratio was $5:3$,then how many years ago were they married?