For this case we propose a rule of three:
$ 50 -------------> 100%
x -----------------> 10%
Where the variable "x" represents the amount of the tip.
[tex]x = \frac {10 * 50} {100}\\x = 5[/tex]
So, the tip was 5 dollars.
If we subtract that amount to what Matt paid at the restaurant we will have the amount of the check before the tip.[tex]55-5 = 50[/tex]
ANswer:
Option D
