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1. It takes 3 pumps 15 hours to fill a swimming pool. How many pumps would it take to fill the pool in 9 hours?

2. It takes 200 tiles to tile a room when each tile covers 36cm2. If I use tiles which covers 25cm2, how many tiles would I       use?

 Mar 17, 2016

Best Answer 

 #2
avatar+600 
+5

Thx Miss Melody :D

 

I had the answers but i just needed 2 know if they were right, n they were!

So thank u

(^_^)

 Mar 17, 2016
 #1
avatar+118587 
+10

Hi Eloise :)

I think it is probably easiest to use a unitary method for these. 

 

1. It takes 3 pumps 15 hours to fill a swimming pool. How many pumps would it take to fill the pool in 9 hours?

3   pumps       take       15 hours

so 1 pump must take 3 times longer than that.      15*3=45hours

1pump         takes      45 hours

 

Now 45 divided by 5 = 9 hous which is the number you want.

If you are going to do it 5 times faster then it will take 5 times more pumps   1*5=5 pumps

So

it will take 5 pumps to fill the pool in 9 hours

 

------------------------------------

 

2. It takes 200 tiles to tile a room when each tile covers 36cm2. If I use tiles which covers 25cm2, how many tiles would I       use?

 

200 tiles    when each is    36cm^2         

If the tiles are only 1cm^2 then the tiles are 36 times smaller and you will need 36 times 200 tiles   36*200 = 7200 tiles (if they are really little just 1cm^2 each)

 

But the ones we want are 25cm^2 each, that is 25 times bigger than the really little ones.  They are a 25 times bigger so we will need to divide the number of tiles by 25

 

7200 divided by 25 = 288 tiles.

So if the tiles cover 25cm^2 each, you will need 288 tiles.

 

 

You had best buy some extra ones because there will be some cut peices that you will not want to use ;)

 Mar 17, 2016
 #2
avatar+600 
+5
Best Answer

Thx Miss Melody :D

 

I had the answers but i just needed 2 know if they were right, n they were!

So thank u

(^_^)

Eloise1st Mar 17, 2016

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