If $A$ and $B$ are in the ratio $4:5$ and the difference of their squares is $81,$ what is the value of $A?$

The annual incomes and expenditures of a man and his wife are in the ratios of $5: 3$ and $3: 1$,respectively. If they decide to save equally and find a balance of ₹ $4000$ at the end of the year (total savings),their incomes were:

The ratio of two numbers is $10: 7$ and their difference is $105$. The sum of these numbers is

$A$ mixture contains alcohol and water in the ratio of $12: 5$. On adding $14 \text{ litres}$ of water,the ratio of alcohol to water becomes $4: 3$. The quantity of alcohol in the mixture is (in $\text{litres}$):

If $4 \, \text{years}$ ago the ratio between the ages of $P$ and $Q$ was $5:6$ and the sum of their ages at present is $52 \, \text{years}$, what is the ratio of their present ages?

If $A: B = 2: 3$,$B: C = 4: 5$,and $C: D = 6: 7$,then $A: B: C: D$ is