Answer:
Mary still owes $662
Explanation:
Step 1: Determine the total cost of the living room:
To determine the total cost of the living room set, we add the $1140, the $90 delivery cost, and the $109 tax:
Total cost = 1140 + 90 + 109
Total cost = 1230 + 109
Total cost = 1339
Thus, the total cost of the living room set $1339.
Step 2: Determine Mary's remaining balance:
Since Mary paid $677 today, we can determine how much more she owes by subtract 677 from 1339:
Remaining balance = 1339 - 677
Remaining balance = 662
Thus, Mary still owes $662.