Find the least common denominator (LCD) of 11/6 and 3/8

The initial distance is 2 2/5 mile or 2.4 miles and the final distance is 8 1/10 mile or 8.1 mile. Therefore the total distance to hike is:

distance = 8.1 – 2.4 = 5.7 miles

Since they will trek at 3 miles per hour, the time needed is:

time = 5.7 mile / 3 miles per hour

time = 1.9 hours

Since they started at 10 am and there is 2 hours allowance from noon, therefore they will reach the marker by noon with 0.10 hour left.