If $U: V = 6: 7$ and $V: W = 21: 6$,then find $U: V: W$.

If $A: B = 3: 4$,$B: C = 4: 5$,and $C: D = 5: 6$,then $A: D$ will be

Present ages of $X$ and $Y$ are in the ratio $5: 6$ respectively. Seven years hence,this ratio will become $6: 7$ respectively. What is $X$'s present age in years?

$P$ varies inversely with the product of $Q$ and $R$. When $Q = 6$ and $R = 12$,$P = 75$. When $Q = 5$ and $R = 10$,what is the value of $P$?

When $X$ is subtracted from the numbers $9, 15$ and $27$,the remainders are in continued proportion. What is the value of $X$?

The railway fares of air-conditioned sleeper class and ordinary sleeper class are in the ratio $4:1$. The number of passengers who travelled by air-conditioned sleeper and ordinary sleeper classes were in the ratio $3:25$. If the total collection was ₹ $37,000$,how much did air-conditioned sleeper passengers pay (in ₹) (in $,000$)?