Two numbers are in the ratio of $5: 7$. If $25$ is subtracted from each,they are in the ratio of $35: 59$. Find the difference of the two numbers.

Seats for Mathematics,Physics and Biology in a school are in the ratio $5:7:8$. There is a proposal to increase these seats by $40\%$,$50\%$ and $75\%$ respectively. What will be the ratio of the increased seats?

$A$ mixture of milk and water is kept in two separate containers. The ratio of milk to water in one container is $5:1$ and in the other container is $7:2$. In what ratio should the mixtures from these two containers be mixed so that the quantity of milk in the new mixture becomes $80\%$?

If $B: A = 2: 3$ and $A: C = 5: 7$,then what is $(A + B) : (B + C)$?

If $5A = 12B = 13C$,find $A:B:C$.

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