Question

Paul can clean a classroom floor in 3 hours. When his assistant helps him, the job takes 2 hours. How long would it take the assistant to do it alone? ​

Answer 1

It would take 6 hours for the assistant to clean the classroom alone.

Step-by-step explanation:

The job in this case is cleaning a classroom.

Paul can clean a classroom in 3 hours

Part of job done by Paul in one hour = 1/3

Similarly, Assistant can clean the same classroom alone but the job this time will take x hours

Part of job done by Paul's assistant = 1/x

Together, Paul and assistant completes the job in 2 hours.

Part of job done by Paul and his assistant together = 1/2

Now, we know that the sum of work done per hour by paul and his assistant separately is equal to the work done by Paul and his assistant together:

Work per hour by Paul + Work per hour by assistant = Work per hour done together

⇒ $\frac{1}{3} +\frac{1}{x} =\frac{1}{2}$

$\frac{1}{x} =\frac{1}{2} -\frac{1}{3} \\\frac{1}{x} = \frac{3-2}{6} \\\frac{1}{x} =\frac{1}{6}$

⇒ x = 6 hours

Hence, the assistant would take 6 hours to clean the classroom alone.

Learn more about work done applications from brainly.com/question/10694003

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