problem 1
A version of this I saw on the labrinth except this one is a lot more complicated (I think I might have seen it on a website while I was transversing or something can't remember where tho).

What you got:
3 men 1 who tells the truth 1 who lies and one randomly says yes and no.

The problem:
1 of the men is holding a key and you only get to ask the men three questions.

problem 2
This one's an easy one with many solutions that we did in logic class

What you got:
A 3 liter jug a 5 liter jug, an infinate amount of water, and a big tub (infinately large)

The problem:
you need to fill the big tub with 9 liters of water

problem 3
This one is a math problem I pulled from a website I'll cite it when everything is done:

What you got: the numbers 3 3 7 7

The problem: you need to get 24 using only addition, multiplication, division and subtraction. everything is in base 10 and no decimal's where used and you need to use all 4 numbers only once.