I'll try to do one every day if I can remember. The first one was pulled by my logic teacher out of a mensa book (sorry about citations souleman). A form of this one comes off of a Microsoft application (details may be different but it's the same problem). remember to keep answers hidden and I'll chime in during the day and see who's right and also I wouldn't be posting this if the most obvious answer was right.

what you have
You have 4 soldiers that need to cross a river but there's only 1 boat and it holds 2 people.

the problem
The soldiers can only cross the river as fast as the slowest person for example if someone who crosses in 7 minutes and someone who crosses in 3 minutes goes it takes 7 minutes. And one person needs to bring the boat back so in the previous senario if those two went over and the three minute guy came back it would be a grand total of 10 minutes 7 there 3 back. What's the shortest amount of time the soldiers can cross the river.

who can do what
the soldiers can cross in 1 minute 10 minutes 5 minutes and 2 minutes.