Given for this problem is: 
 The two trail maps where;
 Trail on the 2ND map = 6 cm
Trail on the 1ST map = 8 cm
 We can say that the scale on first map = 1 cm : 2 km
  
 A) For the first map, the scale factor is 1 cm: 2km. So the actual trail is 8 centimeters * 2 kilometers = 16 km. 
 B) The scale factor of the second map is 16 km / 6 cm = 2.67 km: 1 cm. The length of the actual trail is 16 kilometers.