Answer: The answer is 56.
Step-by-step explanation: Given that we have answered 15 phone calls on Monday, 23 phone calls on Tuesday and 18 phone calls on Wednesday. We are to find the total number of phone calls that we have answered this week.
The total number of calls is the sum of the number of calls answered on Monday, Tuesday and Wednesday.
Therefore, the total number of phone calls answered is given by

Thus, the answer is 56.