The ratio of the number of boys to girls in an institution is $6:5$. If there are $192$ boys in total,find the total number of students in the institution.

The ratio between the present ages of Indira and Lizzy is $3:8$,respectively. After $8 \text{ yr}$,Indira's age will be $20 \text{ yr}$. What was Lizzy's age $5 \text{ yr}$ ago (in $\text{yr}$)?

If two-third of $A$ is four-fifth of $B ,$ then $A : B =?$

The ratio of the father's age to his son's age is $7:3$. The product of their ages is $756$. The ratio of their ages after $6$ years will be:

If $a:b = \frac{2}{9} : \frac{1}{3}$,$b:c = \frac{2}{7} : \frac{5}{14}$,and $d:c = \frac{7}{10} : \frac{3}{5}$,then find $a:b:c:d$.

The monthly salaries of $A, B$ and $C$ are in the ratio $2: 3: 5$. If $C$'s monthly salary is $Rs. 12000$ more than that of $A$,then $B$'s annual salary is (in $Rs.$):