The depth of a body of water can be found by emitting sound pulses reflected from the bottom. If the time interval from emission to detection is 2 s, what is the depth of the water? The correct answer is 1498 m. How do I get it?

It took one second to get to the bottom, one second to return.

depth=velocitysound*time

Isnt the speed of sound in water about 1500 m/s?

http://en.wikipedia.org/wiki/Speed_of_sound

The real issue in this problem is what is the temperature of the water.