What is the full question. I would be able to help if I saw it all.
Find 10% of $19,200 = 1,920
Find 2% of $1,920 = 384
12% = $2,304
19,200 - 2,304 = 16,896 (year 1)
Repeat this until you have your 5th year :)
97.45 / 5 = 19.49 per gallon
and then there is 21.95 per gallon
the better deal would be the 5 gallon bucket for 97.45 because if u buy it this way, it is cheaper by the gallon
I hope this helps you feel free to contact me