To find 28% of $80, we have to first convert 28% to decimal, then multiply $80 with it.
28% = 28/100 = 0.28
Now,
[tex]0.28\times80=\$22.4[/tex]The total amount of bill INCLUDING the tip is the total bill added to the tip amount. That is:
[tex]80+22.4=\$102.40[/tex]$102.40
