Airplane at 19,200 feet descending at a rate of 40 feet per second. Another airplane takes off and ascends at a rate of 60 feet per second. After how many seconds will the airplanes be at the same height? What is this height?

Answer 1

19,200 - 40s = 0 + 60s

Solve for s, then 19,200-40s will be altitude.

Answer 2

192