Problema Solution

Glenn can paint a classroom in 5 hours. His father can do it in 4 hours. How long will it take them if they work together?

Answer provided by our tutors

In 1 hour Glenn can paint 1/5 of the classroom.

In 1 hour the father can paint 1/4 of the classroom.

Let x represent the number of hours that Glenn and his father need to finish the job together.

In 1 hour they will paint 1/x of the classroom.

Now we can write:

1/5 + 1/4 = 1/x

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click here to see the equation solved for x

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x = 20/9 hr

x = 2 hr (2/9)*60 min

x = 2 hr 13.3 min

It will take them 2 hours and 13.3 minutes to finish the work together.