The profile for Spencer indicates that he is currently working towards his PPL so we should not be too surprised that he is asking this type of question.
1 knot is 1 nautical mile per hour.
This means that 98 knots is 98 nautical miles per hour.
There are 60 minutes in an hour so if we divide 98 by 60 we will convert 98 nautical miles per hour into 1.633 nautical miles per minute.
If we then multiply this by 2.5 minutes we will get the number of nautical miles flown in 2.5 minutes. 2.5 X 1.633 is 4.0825