Unit 7 · Finding Procedures
Two Pipes Together — How Long to Fill?
Lesson 5 of 5
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About this lesson
Now for a different flavour of 'finding procedures': combined rate problems. When two pipes (or workers) contribute to the same task simultaneously, the shortcut is to think in rates per hour — not times. Once you see that, the question reduces to adding two fractions.
Chapters
0:00Introduction
0:21The Question
0:59Determining the Hourly Rate for Pipe A
1:21Determining the Hourly Rate for Pipe B
1:44Combining the Hourly Filling Rates
2:14Solving for the Total Collaborative Time
2:32Exam Strategy — The Product Over Sum Formula
3:16Confirming the Final Option
Question
Pipe A can fill a tank in 6 hours.
Pipe B can fill the same tank in 12 hours.
How long does it take to fill the tank if both pipes are open together?
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