Artie and Beth are playing a game. Beth moves one place to the right on a number line each second. Artie moves 2 places each second. Beth starts 1 place ahead of Artie. When Artie catches up to Beth the first time, he must turn around and go back to where he started and then catch up to Beth a second time. Starting from the zero on the number line, how many seconds will it take for Artie to catch up to Beth for the second time?

i'm not sure whether Beth is moving