Andy C. answered • 09/14/18

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DIY water filtering costs

$33 = 3300 cents for 30 gallons =

11 cents per gallon

So the linear function is 38 + 0.33 G where G is the gallons of water

The $38 flat fee is for the water filter and the reusable water.

1 pack of bottled water is 3.16875 gallons ( 24 x 16.9 ounces with 128 ounces per gallon)

Using the filtering system, 3.16875 gallons will cost 0.33 x 3.16875 = $1.0456875

This is 3.99-1.0456875 = 2.94 cheaper per pack of water

38 / 2.94 = 13

So the filtering system will pay for itself after 13 cases of water