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

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?

If $A: B = 2: 5$,$B: C = 4: 3$,and $C: D = 2: 1$,what is the value of $A: C: D$?

₹ $11,550$ has to be divided between $X$,$Y$,and $Z$ such that $X$ gets $\frac{4}{5}$ of what $Y$ gets and $Y$ gets $\frac{2}{3}$ of what $Z$ gets. How much more does $Z$ get over $X$ (in ₹)?

The ratio of two numbers is $3:5$. If both numbers are increased by $8$,the ratio becomes $13:18$. What is the sum of the two numbers?

An employer reduces the number of his employees in the ratio $9:7$ and increases their wages in the ratio $14:15$. Find the ratio in which the total bill of wages increases or decreases.