Total amount paid by Matt at restaurant was 55 dollars. It included a service tip of 10% on check amount.
Total bill is given by sum of check amount and tip amount (if any).
Total Bill = Check amount + Tip amount.
55 dollars = Check amount + 10% of check amount.
55 dollars = 110% of check amount.
55 dollars = 1.10 x check amount.
Check amount = [tex]\frac{55 \;dollars}{1.10} = \frac{550}{11} = 50 \;dollars.[/tex]
Hence, option D is correct, i.e. 50 dollars.
