Your first shot isn't using the phrase "amount tendered" properly. That is the $30 your original post said you give the clerk. You'd get change (or owe more) based on the gallons purchased multipied by the price minus the discount. Your discount is only applied to the first fifteen gallons, so you need to figure if the purchase is for more or less and subtract accordingly.
thats what i was thinking of using, is a True False case statement. Though i honestly dont know how to do the True False case structure.
That is math I could have done in high school. [...]
You have learnt nothing in class? Skipping class?
This seemed slightly harsh when I first read it, but you're not showing much to endear yourself to the collective. Here are a few resources you should use:
I expect that you recognize the "less than or equal to" symbol, the one next to it is "Select". They're both on the Comparison pallet. The multiply is on the Numeric pallet.
How have the tutorials helped?
I figured out where the symbols are and such.
Now i just need to figure out where to place the price per gallon.
Below is what ive got so far. I placed the amount tendered to subtract from the final price to get he discount price.