If $\frac{625}{x} = \frac{x}{1156}$,then what will be the value of $x$?

$A$ 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?

₹ $864$ is divided among $A, B$ and $C$ such that $8$ times $A$'s share is equal to $12$ times $B$'s share and also equal to $6$ times $C$'s share. How much (in ₹) did $B$ get?

The ratio of the present age of Manoj to that of Wasim is $3:11$. Wasim is $12 \text{ yr}$ younger than Rehana. Rehana's age after $7 \text{ yr}$ will be $85 \text{ yr}$. What is the present age (in $\text{yr}$) of Manoj's father,who is $25 \text{ yr}$ older than Manoj?

The students in three classes are in the ratio $4:6:9$. If $12$ students are increased in each class,the ratio changes to $7:9:12$. Then the total number of students in the three classes before the increase is

Calculate the fourth proportional to the numbers $286, 78, 1342$.