If an alloy contains copper and silver in the ratio $3:7$,then the percentage quantity of silver in the alloy is

The ratio of wine and water in a drum is $3:1$. What part of the mixture is taken out and replaced with an equal amount of water so that the ratio of wine and water in the mixture becomes $1:1$?

$A$ certain sum of money was divided between $A$,$B$,and $C$ in the ratio $5: 6: 9$. If $A$ received ₹ $450$,what was the total sum divided?

The prices of a scooter and a television set are in the ratio of $3:2$. If a scooter costs ₹ $600$ more than the television set,then the price of the television set is (in ₹):

The ratio of two numbers is $3:5$. If both numbers are increased by $8$,the ratio becomes $13:18$. What is the sum of the two 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?