A guy decided to go to the brain transplant clinic to refreshen his
supply of brains. The secretary informed him that they had three
kinds of brains available at that time. Doctors' brains were going
for $20 per ounce and lawyers' brains were getting $30 per ounce. And
then there were mathematicians' brains which were currently fetching
$1000 per ounce.
"A 1000 dollars an ounce!" he cried. "Why are they so expensive?"
"It takes more mathematicians to get an ounce of brains," she explained.