If $3A = 4B = 5C$,then $A : B : C$ is

If $3 A = 6 B = 9 C$,what is $A : B : C$?

$A$ milkman makes $20\%$ profit by selling milk mixed with water at $Rs. 9$ per litre. If the cost price of $1 \text{ L}$ pure milk is $Rs. 10$,then the ratio of milk and water in the given mixture is:

The ratio of three numbers is $2: 3: 5$. If the sum of the three numbers is $275$,then what is the largest among the three numbers?

The ratio of ages between $A$ and $B$ is $6: 5$ and the age of each $C$ and $D$ is $\frac{9}{10}$ times that of $B$. The age of $F$ is less than $A$ but greater than $B$. The ratio of ages between $B$ and $E$ is $2: 3$. Also,the age of $A$ is $3 \text{ years}$ less than $E$. What is the ratio of the ages of $A$ and $F$ if all the ages are integers?

Find the compound ratio of $2:7$,$5:3$,and $4:7$.