Answer:
he distance between point A and point B is 17.01 km
Explanation:
If the first stretch of the trip took 1 hour and 40 minutes, this is equivalent to 1 + 40/60 = 2.67 hours. If the friends walked at a speed of 6 km/h for this stretch, then they traveled a distance of 2.67 * 6 = 16.02 km.
If the total trip took 3 hours, and the first stretch took 2.67 hours, then the second stretch took 3 - 2.67 = 0.33 hours. If the friends walked the second stretch at a speed of 3 km/h, then they traveled a distance of 0.33 * 3 = 0.99 km.
The total distance traveled is 16.02 + 0.99 = 17.01 km.
If the friends walked the first stretch at 3 km/h instead, it would have taken them a time of 16.02/3 = 5.34 hours. If they walked the second stretch at a speed of 2 km/h, it would have taken them a time of 0.99/2 = 0.495 hours.
The total time for the trip would have been 5.34 + 0.495 = 5.835 hours. Since this is greater than 3 hours, we know that the friends did not walk the first stretch at 3 km/h. Therefore, the distance between point A and point B is 17.01 km.