Cormac was still finishing his breakfast when his brother Leif left for school. Cormac started to run after Leif when Leif was already 100 meters away. How soon will Cormac catch up to Leif if Cormac runs at a speed of 105 meters per minute, while Leif walks at a speed of 65 meters per minute?
To catch up to Leif, Cormac needs to cover a distance of 100 meters.
Cormac's speed relative to Leif is 105 meters/minute - 65 meters/minute = <<105-65=40>>40 meters/minute.
Therefore, Cormac will catch up to Leif at a rate of 40 meters/minute.
To find out how soon Cormac will catch up to Leif, we can divide the distance Cormac needs to cover (100 meters) by his rate of catching up (40 meters/minute).
Thus, Cormac will catch up to Leif in 100 meters / 40 meters/minute = <<100/40=2.5>>2.5 minutes. Answer: \boxed{2.5}.