Seems to be a bit of a bias in this thread against mathematicians.
Really? I thought the mathematicians had the best answers!
Meh. They're pretty average, and mean.
The fence one shows the wisdom of viewpoint. The fire one shows a trust that others will resolve the issue. What about these great viewpoints is bad?
My engineer, physicist and mathematician jokes have been gathered from mathematicians, and I am one myself. So, maybe, but it's all in good fun 
And the one with the fence is just good sense.
Well, here's one for we engineers then:
A mathematician, a physicist, and an engineer were all given a red rubber ball and told to find the volume.
The mathematician carefully measured the diameter and evaluated a triple integral.
The physicist filled a beaker with water, put the ball in the water, and measured the total displacement.
The engineer grabbed his reference manual, looked up the model of the ball and checked the serial numbers in his ball manufacturers table, cross-referencing the columns for "red" and "rubber" to look up the answer.
I think that's around page 1850 in Machinery's Handbook.