A Simple Problem that seems to elude me

  • Context: High School 
  • Thread starter Thread starter TooManyHours
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Discussion Overview

The discussion revolves around a problem involving the rates at which two individuals, Steve and Dale, can paint a house together and separately. The focus is on determining how long it would take Dale to paint the house by himself, given the time it takes for both to work together and the time it takes Steve alone.

Discussion Character

  • Homework-related

Main Points Raised

  • One participant states that Steve paints at a rate of (1 house)/(30 hours) and calculates that Steve paints 1/3 of a house in 10 hours.
  • Another participant suggests that since Steve paints 1 house in 30 hours, he would paint 1/3 of a house in 10 hours, implying Dale must paint the remaining 2/3 of the house in that time.
  • A different participant proposes that to find Dale's time to paint the house alone, one should multiply the time together (10 hours) by a ratio derived from their individual rates, concluding that it would take Dale 15 hours to paint the house by himself.
  • One participant expresses agreement with the conclusion that Dale would take 15 hours, indicating it as the correct answer.

Areas of Agreement / Disagreement

There is a general agreement among participants that Dale would take 15 hours to paint the house by himself, although the reasoning and calculations leading to this conclusion are not unanimously accepted.

Contextual Notes

Some assumptions about the linearity of painting rates and the method of combining rates are present but not explicitly stated. The calculations involve multiple steps that may not be fully detailed or agreed upon by all participants.

Who May Find This Useful

Individuals interested in rate problems, particularly in the context of work and time, may find this discussion relevant.

TooManyHours
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My mind is blank for some reason as I can't seem to figure out how to set up this problem...

It takes Steve and Dale together 10 hours to paint a house.

Steve takes 30 hours by himself.

How long would it take Dale to paint the house my himself?

Thanks...
 
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TooManyHours said:
My mind is blank for some reason as I can't seem to figure out how to set up this problem...

It takes Steve and Dale together 10 hours to paint a house.

Steve takes 30 hours by himself.

How long would it take Dale to paint the house my himself?

Thanks...
Steve paints houses at a rate of (1 house)/(30 hours). Assuming Steve has a linear rate of painting, we have 3*(1/30) = 1/10, which means Steve paints 1/3 of a house in 10 hours. Can you continue ? :smile:
 
OK,

Steve paints 1 house in 30 hours or 1/3 house in 30/3 = 10 hours

That means that Dale has to paint the other 2/3 of the house in the 10 hour period.

Working backwards for Steve, to get from the 10 hours together to his single total, we multiply 10 by 3/1 = 30 hours.

So, for Dale, we have to multiply 10 * 3/2 to get 30/2 or 15 hours to paint the house by himself.

I think...
 
Yes,15hrs is the correct answer... :smile:

Daniel.
 
Thanks...
 

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