A leaky valve on the water meter overcharges the residents for one gallon of water every 2 1/5 months. The overcharged amount w
varies directly with time t. Find the equation that models this direct variation. How many months it will take for the residents to be overcharged for 7 gallons of water?
The overcharge amount w, in this case, would be 1 gallon of water. The time t, in this case, would be 2 1/5 month. Then the equation to count the overcharge amount would be: w *1 = t *2 1/5 w = 2 1/5 t
Then, for 7 gallons of water, you need to replace w with 7. The calculation would be: w = 2 1/5 t 7= 2 1/5 t t= 7/ (2 1/5)= 3.18 months
