Compare the decmals 13.03 and 13.30

13.03 is smaller than 13.30
Because 03 is smaller than 30 (comparing the decimal portions only)

So
13.03 < 13.30
The smaller side is always on the pointy side of the inequality sign. Or put another way, think of it as an alligator mouth and the alligator always eats the bigger amount

Ican't do any of the other stuff, but i can get you started. the answer, i believe, is $2.50.