$43 per 10 gallon
Let's divide the dollar amount by gallons to get unit rate.
Thus,
43/10
= 4.3 dollars per gallon
Then,
62.05 dollars per 15 gallons, we can divide same way to get the unit rate. Thus,
62.05/15 = 4.14 dollars per gallon
Obviously, the 2nd one is the better deal!
The unit rate is $4.14 per gallon.