So I’m assuming you’re saying that 1 cm=6 m so if the kitchen is 4 cm in the drawing it has to be scaled up by 6 for each centimeter. So 4*6=24 so the kitchen is 24 meters long. Hope this helps!
no, it is constant for a while then changes at 90gallons
$1,040 is how much you would have remaining at the end if that's what you are looking for.
Dollars is the dependent quantity because the amount you pay depends on how many gallons you've pumped.