Step-by-step explanation:
use mathaway! it helps a lot
Answer: 2.5 hours.
so he already down 20 ft so he ascends (goes up) 9 feet, so hes at 11 feet right now. then he descends 12 (goes down) feet so hes at 23 feet. lastly he ascends 15 feet (goes up) more. so the answer is 8
Answer:
23 + 0
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