Water flows into a tank having the dimensions of its base given as $$200 m \times 150 m$$ through a rectangular pipe having dimensions given as $$1.5m \times 1.25 m$$ at 20 kmph. In what time (in minutes) will the water rise by 2 metres?

Correct option is B

Given:

Base area of the tank =$$200 \text{m} \times 150 \text{m}$$​​

Area of cross-section of the pipe =$$1.5 \text{m} \times 1.25 \text{m}$$​​

Velocity of flow = 20 km / h.

Formula Used:

Discharge of water = Volume of a tank upto water level in the tank.

Discharge of water = Area of cross-section of pipe × Velocity of flow

Solution:

Let in 'x' hours the water level in the tank rise by 2 m.

Discharge of water = Volume of a tank upto water level in the tank.

Discharge of water = Area of cross-section of pipe × Velocity of flow

=> Area of cross-section of pipe × Velocity of flow = Volume of a tank upto water level in the tank

=> 1.5× 1.25 × 20000 × x = 200 × 150 × 2

=> x = $$\frac 85$$​​

=> x = 96 minutes

∴ The water level in the tank rise by 2 m in 96 minutes.