Answer:
The waitress earned a total of 33 dollars
Step-by-step explanation:
Step 1: Determine total earnings from wages;
Total earnings from wages=Earnings per hour×number of hours worked
where;
Earnings per hour=3 dollars an hour
Number of hours worked=3 hours
replacing;
Total earnings from wages=(3×3)=9 dollars
Step 2: Determine total earnings from tips
Total earnings from tips=(12+5+7)=24 dollars
Step 3: Calculate total money earned
Total money earned=Total earnings from tips+total earnings from wages
where;
Total earnings from tips=24 dollars
Total earnings from wages=9 dollars
replacing;
Total money earned=(9+24)=33 dollars
The waitress earned a total of 33 dollars