Answer:
The duration of the calls is:
Step-by-step explanation:
We can assume that the second call was longer than the first (10 minutes how says in the exercise), then we replace the duration of the calls how is shown below:
With the information given in the paragraph we can do the next formulas:
We replace the second formula in the first:
And we operate:
How the second call was 10 minutes longer than the first, we just add 10 to X and we'll find Y:
And how 18 + 28 = 46, we can be sure that they are the times of the calls.