A scientist uses a submarine to study ocean life. She begins at sea level, which is an elevation of 0 feet.
She travels straight down for 20 seconds at a speed of 2.4 feet per second.
She then travels directly up for 48 seconds at a speed of 0.5 feet per second.

After this 68-second period, how much time, in seconds, will it take for the scientist to travel back to sea level at 4.3 feet per second? Round your answer to the nearest tenth of a second. plz help with this im timed and my teachers not helping