Question

Mark (✓) against the correct answer:
The rates of working of two tapes A and B are in the ratio 2 : 3. The ratio of the time taken by A and B respectively to fill a given cistern is
(a) 2 : 3
(b) 3 : 2
(c) 4 : 9
(d) 9 : 4

Answer 1

(b) 3:2

$$\begin{gathered} \mathrm{Rates}\mathrm{at}\mathrm{which}\mathrm{taps}\mathrm{A}\mathrm{and}\mathrm{B}\mathrm{work}=2:3 \\ \mathrm{The}\mathrm{ratio}\mathrm{of}\mathrm{time}\mathrm{taken}\mathrm{by}\mathrm{taps}\mathrm{A}\mathrm{and}\mathrm{B}\mathrm{to}\mathrm{fill}\text{the}\mathrm{cistern}=\frac{1}{\mathrm{Rates}\mathrm{at}\mathrm{which}\mathrm{taps}\mathrm{A}\mathrm{and}\mathrm{B}\mathrm{work}} \\ =\frac{1}{{\displaystyle \frac{2}{3}}}=\frac{3}{2}=3:2 \end{gathered}$$