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

The electricity bill of a certain establishment is partly fixed and partly varies as the number of units of electricity consumed. When in a certain month $540$ units are consumed,the bill is $Rs. 1800$. In another month $620$ units are consumed and the bill is $Rs. 2040$. In yet another month $500$ units are consumed. The bill (in $Rs.$) for that month would be:

The total of the ages of Jayant,Prem and Saransh is $93$ years. Ten years ago,the ratio of their ages was $2: 3: 4$. What is the present age (in years) of Saransh?

If $24$ is deducted from $45 \%$ of a number,the result becomes $48$. What will be $\frac{3}{8}$ part of that number?

Three numbers are in the ratio $2:3:4$. If the sum of their squares is $1856$,then the numbers are:

If $A: B = \frac{1}{2}: \frac{3}{8}$,$B: C = \frac{1}{3}: \frac{5}{9}$ and $C: D = \frac{5}{6}: \frac{3}{4}$,then the ratio $A: B: C: D$ is