Water is flowing at the rate of 5 km/h through a pipe of diameter 14 cm into a rectangular tank which is 50 m long 44 m wide. The time taken (in hours) for the rise in the level of water in the tank to be 7 cm is

Let the time taken to fill the tank = $$x$$ hours
$$\eqalign{ & \Rightarrow \left( {\pi {r^2}h} \right) \times x = 50 \times 44 \times \frac{7}{{100}} \cr & \Rightarrow x = \frac{{50 \times 44 \times 7 \times 7 \times 100 \times 100}}{{22 \times 7 \times 7 \times 100 \times 5000}} \cr & \Rightarrow x = 2{\text{ hours}} \cr} $$