Question

An empty rectangular tank with base area 2400 sq.cm is filled with water from two taps. One fills 12 litres of water per minute and the other 8 litres per minute. After both taps are open for 6 minutes. What will be the depth of water in the tank?
1. 75 cm
2. 24 cm
3. 50 cm
4. 100 cm

Answer 1

Correct Answer - Option 3 : 50 cm

Given 

Efficiency of one pipe per minute = 12 liters

Efficiency of another pipe per minute = 6 liters

Formula Used 

Efficiency × Time = Work done 

Volume = Rate of flow × Time

Volume = Area of base × Height

Calculation 

Both the pipe fill the water in 6 minutes = (12 + 8) × 6 = 120 liters 

1 liter = 1000 cm³

⇒ 120 liters = 120000 cm³

Volume = 120000 cm³ 

⇒ 2400 × h = 120000 cm²

⇒ h = 50 cm 

∴ The depth of water in the tank is 50 cm