Answer:
900ft
Explanation:
He starts at 800 feet and goes 200 feet up to the first rest stop.
Rest Stop 1 = 1000ft
He went down 400 feet to the second.
Rest Stop 2 = 600ft
He went up 500ft to the third rest stop.
Rest Stop 3 = 1100ft
The average is:
(1100+600+1000) / 3
= 900ft :)
Hope this helps!
