Answer:
Therefore, the Forest Service will open trials on April 23rd.
Explanation:
On January 15th, snow pack = 150 inches.
Snow pack decreases 11 inches per week.
The trials for hiking would be opened when the snow will be gone.
The snow will be gone in the number of weeks it takes to decease.
Number of weeks required =
= 13.64 weeks
Number of weeks required ≅ 14
Thus, it would take a maximum of 14 weeks for the snow to be gone from January 15th.
Therefore, the Forest Service will open trials on April 23rd.