Question

If 1/4 gallons of water are enough to fill 7/10 of the pool how much water is nessacary to fill in the entire pool

Answer 1

Answer:  5/14 gallons

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Work Shown:

1/4 = 0.25

7/10 = 0.70 = 70%

We are told that 0.25 gallons of water fills 70% of the pool

We want to find how many gallons of water (call it x) are needed to fill 100% of the pool.

Set up the proportion below and solve for x

(0.25 gallons)/(70% filled) = (x gallons)/(100% filled)

0.25/70 = x/100

0.25*100 = 70x ....... cross multiply

25 = 70x

70x = 25

x = 25/70

x = (5*5)/(5*14)

x = 5/14 gallons

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An alternate method:

1/4 gallons = 7/10 pools filled

(10/7)*(1/4 gallons) = (10/7)*(7/10 pools filled)

(10*1)/(7*4) gallons = (10*7)/(7*10) pools filled

10/28 gallons = 1 pool filled

(5*2)/(14*2) gallons = 1 pool filled

5/14 gallons = 1 pool filled

In the second step, I multiplied both sides by 10/7 so that the "7/10" turns into "1".

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Yet another alternate method:

1/4 = 10/40

7/10 = 28/40

We need 10/40 gallons of water to fill 28/40 of one pool. We can multiply both fractions by 40 to indicate that 10 gallons of water will fill up 28 pools.

So we have this ratio

10 gallons : 28 pools

Dividing both parts by 28 tells us how many gallons are needed for one pool

10 gallons : 28 pools

10/28 gallons : 28/28 pools

10/28 gallons : 1 pool

5/14 gallons : 1 pool