MAPE and sMAPE

In the theory section, we mention how MAPE is known to treat overestimation and underestimation unequally.

Let's consider the following scenario. We have two sets of true targets and predictions:

$$\text{Case}_1: Y = \{90\}, \, \hat{Y} = {70} \\ \text{Case}_2: Y = \{70\}, \, \hat{Y} = {90}$$

Calculate the MAPE for the two cases above and answer the following question: which case showed worse score?

Your answer function looks like this:

$$\text{Answer}= \begin{cases} \text{MAPE}_1, & \text{if }\ \text{Case}_1\, \text{showed worse performance} \\ \text{MAPE}_2, & \text{otherwise} \end{cases}$$

Round the answer up to the third decimal.