If $A: B = 8: 15$,$B: C = 5: 8$,and $C: D = 4: 5$,then $A: D$ is equal to:

Three numbers $A, B$ and $C$ are in the ratio of $12: 15: 25$. If the sum of these numbers is $312$,find the ratio between the difference of $B$ and $A$ and the difference of $C$ and $B$.

If two numbers are in the ratio $2:3$ and the ratio becomes $3:4$ when $8$ is added to both the numbers,then the sum of the two numbers is

If $P: Q = 8: 15$,$Q: R = 5: 8$,and $R: S = 4: 5$,then $P: S$ is equal to

There is a ratio of $5:4$ between two numbers. If $40\%$ of the first number is $12$,then $50\%$ of the second number is:

What is the fourth proportional to $24, 120$ and $22$?