$20.00 divided by $2.70 a gallon=7.40 gallons
19 gallon tank divided by 16 lights=1.18 gallons per light
7.40 divide by 1.18=6.27 lights off, so you need "7 lights off" to get the whole $20.00 in the tank.
Correct me if I'm wrong!
__________________
We can do without any article of luxury we have never had; but once obtained, it is not in human nature to surrender it voluntary.
|