If $A: B = 3: 4$ and $B: C = 8: 9$,then find the value of $A: B: C$.

Ajay,Aman,Suman,and Geeta rented a house and agreed to share the rent as follows:
Ajay:Aman $= 8: 15$,Aman:Suman $= 5: 8$,and Suman:Geeta $= 4: 5$. The part of the rent paid by Suman will be

Sachin is younger than Rahul by $4$ years. If their ages are in the respective ratio of $7:9$,how old (in years) is Sachin?

An amount of money is to be divided among $P$,$Q$,and $R$ in the ratio of $3:5:7$,respectively. If the amount received by $R$ is ₹ $4,000$ more than the amount received by $Q$,what will be the total amount (in ₹) received by $P$ and $Q$ together?

An amount of $Rs. 2430$ is divided among $A$,$B$,and $C$ such that if their shares are reduced by $Rs. 5$,$Rs. 10$,and $Rs. 15$ respectively,the remainders are in the ratio of $3:4:5$. Then,$B$'s share was (in $Rs.$):

$A$ 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: