Question 748598
After 1 hr Alan has travelled 55 mi. This means that together they must now travel 195 mi

starting after 1 hr...
Distance Alan travels: 55t
Distance Dave travels: 65t

55t+65t = 195

this gives t=195/120=1 and 5/8 hrs


so total time is 2 and 5/8 hrs (2 hrs, 37.5 minutes)



:)