If you shout into the grand canyon, your voice travels at the speed of sound (340 m/s) to the bottom of the canyon and back, and you hear an echo. how deep is the grand canyon at a spot where you can hear your echo 5.2 seconds after you shout?

Given:
The speed of sound is  340 m/s
Time for the echo is 5.2 s.

Let h = the depth of the canyon.

Because the sound of your voice travels to the bottom of the canyon and back to your ear, the total distance traveled is 2h.

By definition,
distance = velocity * time.
Therefore
2h = (340 m/s)*(5.2 s) = 1768 m
h = 884 m

The depth is 884 m.

Special care would be an answer