Exercise 3 solution (Python)

def paces(metres, per_100m):
    return round(metres / 100 * per_100m)

leg = 900
per_100 = 62
road = leg + 300

print("(a) expected paces to target:", paces(leg, per_100))
print("(b) stop and think at:", paces(leg * 1.2, per_100))
print("(c) paces to the road:", paces(road, per_100))
print("Limit before the road?", paces(leg * 1.2, per_100) < paces(road, per_100))

Output:
(a) expected paces to target: 558
(b) stop and think at: 670
(c) paces to the road: 744
Limit before the road? True

The 120% limit (670 paces, 1080 m) comes before the road (744 paces, 1200 m), so the limit gives you a warning about 74 paces before you would reach the catching feature. If you reach 670 paces without finding the target, stop, do not carry on to the road, and go through the relocation steps: last certain point, estimated distance, features, bearings if needed.