Since @Cellexya didn't post anything, I'll do
You enter a lab on a mountain, pull a lever, and mutant zombies (with night vision) appear, the only way to escape is to cross a bridge, you've gotten a head start. You cross the bridge in a minute, the professor's assistant crosses it in 2 minutes, the janitor crosses it in 5 minutes and the professor in 10 minutes. By the professor's calculations the zombies will reach you in 17 minutes. The bridge can only take 2 people at a time and it is so dark, that you can barely see and the old lanter you have, can only light a small area. Can you get everyone to the other side of the bridge before the zombies arrive?
REMEMBER:
No more than 2 people can cross the bridge together
Anyone crossing th bridge must either have the lantern or be very close to it
Any of you can safely wait in the dark on any of the 2 sides
And finally, there are no tricks to this, you can't swing in the ropes, use the bridge as a raft, befriend the zombies or carry on your back anyone.