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Question 810555: 3 people can paint 5 walls in 41 minutes.
How many minutes will it take for 8 people to paint 8 walls? Round to the nearest minute.
Found 2 solutions by Okeke_Christian, josmiceli:
Answer by Okeke_Christian(26)   (Show Source):
You can put this solution on YOUR website! Let us dissect the question carefully to fully comprehend the implications involved and then, we can easily find our answer.
Now, let's look at it practically;
If it takes 3 men 41minutes to paint 5 walls, how many minutes do you think it will take only one man (working at the same rate)?
Thrice the time of course!
That means;
It takes 1 man  seconds to paint those 5 walls.
(Please note I converted the time to seconds for ease in division operations.
It takes 1 man  seconds to paint 5 walls.
GOOD! We're doing well.
Now, at the same rate, how long will it take to paint one wall?
You thought right! Just one-fifth of the time for 5 walls.
That means,
It will take 1 man  seconds to paint 1 wall.
and that is
= seconds for a single wall.
Good! Now we know how long it will take for ONE man to paint ONE wall.
How long then will it take for ONE man to paint 8 walls?
Right - 8 times the time taken for a single wall!
i.e. It will take  seconds to paint 8 walls.
= seconds for 8 walls.
DON'T GIVE UP, WE'RE ALMOST THERE.
It takes 1 man 11,808 seconds to paint 8 walls, how long then will it take 8 men to do the same job?
one-eight of the time!
So, it'll take 8 men  seconds to paint 8 walls.
Therefore, it'll take 8 men 1476seconds to paint 8 walls.
Remember, we were asked to leave our answer in minutes (to the nearest minute actually).
1476 seconds = 24 minutes and 36 seconds.
36 seconds is just over the half-mark, friend; so we're left with 25 minutes of work time for our painter-friends.
SO, IT'LL TAKE OUR FRIENDS AT BERGER PAINTS 25 MINUTES TO DO THE JOB.
Understood?
(PS: we always assume they all work at the same rate - say, they're programed machines.)
Answer by josmiceli(19441)  (Show Source):
You can put this solution on YOUR website! 3 people can paint 5 walls in 41 minutes
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It would take 3 people 8 times as long to paint 40 walls
so, 3 people paint 40 walls in 328 minutes
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3 people can paint 1/5 as many walls in 1/5 of that time,
so, 3 people paint 8 walls in 65.6 minutes
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24 people can paint 8 walls in 1/8 of that time
so, 24 people paint 8 walls in 8.2 min
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1/3 as many people take 3 times as long to paint
the same number of walls
so, 8 people can paint 8 walls in 24.6 minutes
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