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# If it takes 3 people 5 hours to paint a room... watch

1. Hi all,

I'm stuck solving the following problem:
3 people 5 hours to paint a room how many people does it take to paint the room in 2 hours?

Any assistance is greatly appreciated!

CC
2. If it takes 3 people 5 hours to paint a room then it takes 15 hours in total. 3 people, each working 5 hours each is 15 hours.

If the entire room takes 15 hours to paint and you want to paint it in 2 hours then you need 15/2 people, or 7.5 people. This is not realistic so you need 8 people.

Of course you could factor in other stuff, is the room big enough for 8 people, will they get in each others way and so on but this would be overcomplicating it at GCSE level.
3. (Original post by Acsel)
If it takes 3 people 5 hours to paint a room then it takes 15 hours in total. 3 people, each working 5 hours each is 15 hours.

If the entire room takes 15 hours to paint and you want to paint it in 2 hours then you need 15/2 people, or 7.5 people. This is not realistic so you need 8 people.

Of course you could factor in other stuff, is the room big enough for 8 people, will they get in each others way and so on but this would be overcomplicating it at GCSE level.
Yup, or you could see it like this. If it takes 3 people 5 hours, then it takes 1 person 15 hours. If you want it completed in 2 hours, then you need to need 15/2 which is 7.5. Essentially you are working at twice the rate (which is why you it is half the time it takes for 1 person). 7.5 rounds to 8 since there is no half a person.

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4. Many thanks Acsel & Moltenmo!!!
5. (Original post by kcmaths)
Hi all,

I'm stuck solving the following problem:
3 people 5 hours to paint a room how many people does it take to paint the room in 2 hours?

Any assistance is greatly appreciated!

CC
to get it done in 1 hour you would need 5 times as many people...3x5 = 15

so to get it done in 2 hours.... ?

( you have to assume that the work rate is not impaired by people bumping into each other etc )

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Updated: January 8, 2017
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