The cost of a year's supply of a certain brand of bottle water based on the recommended consumption of 64 oz per day, at the supermarket price of $ 3.99 for a six pack of half litter bottles is $ 918.78. This is $ 918. 35 more than the cost of drinking the same amount of tap water for a year. What is the cost of drinking tap water for a year?

$0.43

Step-by-step explanation:

We know that the cost to drink tap subtracted from the cost to drink bottled water equals 918.35. We can model this in an equation:

918.35 = 918.78 - t

t represents the cost of drinking tap for a year.

Lets subtract both sides by 918.78 to isolate the t

-0.43 = -t

divide both sides by -1 to isolate the t

0.43 = t

it costs $0.43 to drink tap water for a year.