Answer: 4 kilometers.
Step-by-step explanation:
You need to analize the information provided in the exercise.
You know that:
Knowing this you can find the total kilometers of the hike (which is the 100% of the hike) with the following expression:
[tex]\frac{16}{80}=\frac{total}{100}\\\\total=(100)(\frac{16}{80})\\\\total=20\ km[/tex]
Let be "x" the amount of kilometers Allison has left in the hike. This can be found with the following subtraction:
[tex]x=20\ km-16\ km\\\\x=4\ km[/tex]