Here's mine :
You have 2 US coins that equal 35 cents but one of the coins is not a dime. How do you get 35 cents?
Three travelling salesman share a hotel room for $30. After checking in, the manager tells the bellhop - "I forgot the room was on special for $25. Here's $5 to give them back." In the elevator, the bellhop doesn't know how to split $5 three ways, so he pockets $2, and gives each salesman $1. So each salesman paid $9. Three times nine is $27. Plus $2 in the bellhop's pocket is $29. Where's the other $1 ?
 Hominid
                                                
                                                Level 7
                                                Mar 18, 2018
                                            
                                                
                                                    Hominid
                                                
                                                Level 7
                                                Mar 18, 2018                                            
                                        I love this one. It had me stumped the first time I heard it
@Katastrophe1969 Bazinga! Well caught my friend... Math can be strange.
@Katastrophe1969 My kinda dude.
the first koan of buddism. what is the sound of one hand clapping?
 michaelj
                                                
                                                Level 7
                                                Mar 18, 2018
                                            
                                                
                                                    michaelj
                                                
                                                Level 7
                                                Mar 18, 2018                                            
                                        Snap your fingers
Silly.
Why do farts stink?
So deaf people can enjoy them, too.
 LimeySteve
                                                
                                                Level 7
                                                Mar 18, 2018
                                            
                                                
                                                    LimeySteve
                                                
                                                Level 7
                                                Mar 18, 2018                                            
                                        A farmer planted five straight rows of trees with four trees in each row for a total of ten trees.
How?
 WTSharpe
                                                
                                                Level 6
                                                Mar 18, 2018
                                            
                                                
                                                    WTSharpe
                                                
                                                Level 6
                                                Mar 18, 2018                                            
                                        One of my favourites goes something along the lines of.
"One day, the younger of a pair of twins celebrated their birthday. Two days later, the elder twin celebrated theirs. How?"
 NicoleCadmium
                                                
                                                Level 7
                                                Mar 18, 2018
                                            
                                                
                                                    NicoleCadmium
                                                
                                                Level 7
                                                Mar 18, 2018                                            
                                        A birthday and the celebration of a birthday can different on dates?
@4EvanSake They're celebrating on the anniversary of their birth, and they are twins from the same mother.
@Katastrophe1969 That's half of the solution. You're on the right track 
Something involving the crossing of the International Date Line during their birth?
@WTSharpe Spot on. The mother gives birth on a ship. The first twin is born on 1st March, the ship crosses the date line and the second twin is born on 28th Feb. The year that they are currently celebrating is a leap year, so 29th Feb occurs between both of their birthdays.
In the movie Labyrinth
The girl faces two doors guarded by two guards. One door is certain death the other her path forward. One guard always tells the truth one guard always lies. She can have one question.
 Anonbene
                                                
                                                Level 8
                                                Mar 18, 2018
                                            
                                                
                                                    Anonbene
                                                
                                                Level 8
                                                Mar 18, 2018                                            
                                        I saw this as 'two brothers living at a fork in the road, one always tells the truth but the other always lies.' I never looked up the official answer, but my guess was that you ask "What would the other one tell me?" and then do the opposite.
(Just realised this one's duplicated a few posts down.)
Are we assuming each guard is guarding a particular door and they know which is the door to certain death? If so got it.
@NicoleCadmium
Yes
One of the coins isn't a dime..clever!
This riddle came from the MENSA book we used to play with as kids.
You are traveling through a country of people who are either green or red. All the green people must tell the truth, and all the red people always lie. You reach an intersection at dusk and want to know which way to turn to reach the nearest town. There is a man standing nearby, but it's almost dark and you can't tell what color he is.
What one question could you ask to get correct directions that wouldn't matter which color the man was?
 birdingnut
                                                
                                                Level 8
                                                Mar 18, 2018
                                            
                                                
                                                    birdingnut
                                                
                                                Level 8
                                                Mar 18, 2018                                            
                                        Is the one where you say, which direction will the other one send me?