The ratio of three numbers is $3:4:5$ and the sum of their squares is $1250$. The sum of the numbers is:

Two candles of the same height are lighted at the same time. The first is consumed in $8 \text{ hours}$ and the second in $6 \text{ hours}$. Assuming that each candle burns at a constant rate,in how many hours after being lighted,the ratio between the height of the first and second candles becomes $2:1$?

If $A : B = 7 : 9$ and $B : C = 8 : 11,$ find $A : B : C$.

If $0.75 : x :: 5 : 8,$ then $x$ is equal to

The salaries of $A, B, C$ are in the ratio $2: 3: 5$. If increments of $15\%, 10\%,$ and $20\%$ are allowed respectively in their salaries,then what will be the new ratio of their salaries?

Three numbers $A, B$ and $C$ are in the ratio $12: 15: 25$. If the sum of these numbers is $364$,find the ratio between the difference of $B$ and $A$ and the difference of $C$ and $B$.