[LBJ]

*******SPOILER/CORRECT ANSWER**********





Ok, I was the first person to click on this thread and have been thinking about this for about 19 minutes. I was about to give up and then I realized there had to be a logical way that didn't involve 1 keep going back and forth with 2, 5, and 10.

1 and 2 cross- thats 2 minutes
1 come back- thats 1 minute
5 and 10 cross-thats 10 minutes
2 comes back- thats 2 minutes
1 and 2 cross- thats 2 minutes