Net rate from volumetric velocities with one outlet Taps A, B, C have velocities 42 L/h, 56 L/h and 48 L/h. A and B are inlets; C is an outlet. If all three are opened together from empty and the tank fills in 16 hours, what is the tank’s capacity?
Aptitude
Pipes and Cistern
Difficulty: Easy
Choose an option
Answer
Correct Answer: 800 L
Explanation
Introduction / Context:When volumetric flow rates are given directly, the net inflow is the algebraic sum of the listed L/h values (taking the outlet as negative). Capacity equals net rate multiplied by time to fill.
Given Data / Assumptions:
- A = +42 L/h, B = +56 L/h, C = −48 L/h.
- Tank fills in 16 h.
- Flows are steady and additive.
Concept / Approach:Net flow = 42 + 56 − 48. Capacity = net flow * time.
Step-by-Step Solution:
Net = 50 L/hCapacity = 50 * 16 = 800 LVerification / Alternative check:Reverse check: 800 / 16 = 50 L/h, which equals 42 + 56 − 48.
Why Other Options Are Wrong:960, 1600, 2346 are inconsistent with the stated time and flows.
Common Pitfalls:Adding the outlet as positive instead of subtracting.
Final Answer:800 L