Answer:
6.6 km
Step-by-step explanation:
The first day they cover 0.28 of the total 18.5 km hike, therefore, they cover: 0.28 * 16.5 = 5.18 km.
On each of the second and third days they cover half of what is left.
So what was left to cover from the first day is: the total 18.5 km minus 5.18 km. That is: 18.5 - 5.18 = 13.32 km.
Half of this distance is : 13.32 km divided by 2 which equals 6.66 km
