A mathematician and a physicist were asked the following question:

A mathematician and a physicist were asked the following question:
Suppose you walked by a burning house and saw a hydrant and
a hose not connected to the hydrant. What would you do?
P: I would attach the hose to the hydrant, turn on the water, and put out
the fire.
M: I would attach the hose to the hydrant, turn on the water, and put out
the fire.
Then they were asked this question:
Suppose you walked by a house and saw a hose connected to
a hydrant. What would you do?
P: I would keep walking, as there is no problem to solve.
M: I would disconnect the hose from the hydrant and set the house on fire,
reducing the problem to a previously solved form.