Miscellaneous quizzes.

Inspired: A , a , a and a is running away from the . They come to a bridge that can only support 2 of each of them at most, and it has many holes therefore a torchlight is required to cross the bridge without falling, and there is only one. The can cross the bridge in 5 minutes, the in 10, the in 20 and the in 25, if 2 of each decide to cross together, they cross at the speed of the slower one. The is coming at them at full speed and will reach this side of the bridge in 60mins, it threatens to do anything to harm the team, including cutting off the bridge. Will the , , and make it alive, how?

and first, then goes back, thats 15min, and cross bridge, then goes to the other side, thats 50min, and + cross the bridge, so all in exactly 60min?