Step-by-step explanation:
I don't know the area of the glass front of your largest building.
but just think :
1 gallon of fluid costs $12
1 gallon cleans 5000 ft²
so, now, find the area (ft²) of that glass front and see what number you have to multiply 5000 with to get the area of the glass front.
then, you have to multiply $12 with that same number, and you get the price.
let's say the building's glass front has 10000 ft².
what do I have to multiply with 5000 to get 10000 ?
this is the same question as how often fits 5000 into 10000 ? which is 10000 / 5000 = 2
and 12×2 = $24 as total cost to clean it.
our the building's glad front has 2500 ft².
what do I have to multiply with 5000 to get 2500 ?
this is the same question as how often fits 5000 into 2500 ? which is 2500 / 5000 = 1/2
and 12 × 1/2 = $6 as total cost to clean it.
