Ask a parent to help you with it because I'm not so sure maybe 12/60?
The correct answer would be C., I believe, because you take the opposite of the coordinate and subtract one. Hope this was helpful! (:
First the person with a flashlight and one of his friends cross the bridge. After that same person with a flashlight comes back and leads another friend to the other side. Finally he comes back again and leads the last of them.
Number of times that he will have to cross the bridge is 5 ( five ).
