A park contains several types of trees. The table below shows the number of some tree types and the probability of selecting a Maple tree:
| Tree Type | Number of Trees |
|---|---|
| Oak | 40 |
| Maple | 30 |
| Pine | 50 |
| Birch | ? |
If a tree is selected at random from the park, and the probability that it is a Maple tree is , what is the probability that the selected tree is NOT an Oak tree?
0.60
0.70
0.80
0.90
