Answer: $19.10
Explanation:
To be honestly im not sure if this is 100% correct but, i did the work so it should be. So what i did was move the decimal from $27.50 one place to the left which is= 2.750. i then rounded the easiest number which then gave me the answer $2.80. Now the percentage, its 30% so you then change it to .30
then you multiply that number (.30 which is basically 3) with $2.80.
$2.80
x .30
--------
you then get $8.40
which is the total cost of tax AND tip.
you subtract that with the cost of the dinner. ( $27.50 - $8.40 ) and you get the answer $19.10! I hope this helps! :))