If you are buying something that cost $15 and sale tax is 6%, you can calculate final bill trough proportions:
$15:100%=$x:106%
100x=106*15, x=(106*15)/100, x=$15.9 is final bill.
You can also use easier way: $15+0.06*$15=$15.9
Explanation for 2nd way: Cost is $15, on that you need to add 6% of $15: (6%/100%)*$15 and that is 0.06*15.
Answer:
$16
Step-by-step explanation:
Round : $80.36 : $80
Equation : 20% of 80
Answer : $16
Sidenote: I hope this answers your questions!
Answer: 11.2 because I know trust me. I did a worksheet with this same question and got 11.2 and it was correct.