Rehearsing a bit of math I come across this problem I've got a hard time to get a grip on.

_______

A person shoots at a barrel, two seconds later he hears the bullet hit the barrel. The speed of sound is 340m/s and the average speed of the bullet is 650m/s.

What is the distance between the shooter and the barrel?

--------

Thank you for your help

Edit: Maybe the distance can be expressed as x and ...?