Exercise 1 solution

Route A: 6 km, 200 m ascent
  distance: 6 / 5 x 60 = 72 min
  climb: 200 / 100 x 10 = 20 min
  total: 92 min

Route B: 4.5 km, 450 m ascent
  distance: 4.5 / 5 x 60 = 54 min
  climb: 450 / 100 x 10 = 45 min
  total: 99 min

Route A is 7 minutes quicker on paper even though it is 1.5 km longer, because Route B climbs 250 m more.

Time is not the only factor. Route B is shorter, so it is the better choice if the group wants less distance, or if Route A crosses ground that is exposed, boggy or hard to navigate. Route A is easier to navigate if it follows a path, or has more handrails and catching features.
Whichever is chosen, note the other as an alternative, and record the decision on the route card.