"Nasruddin," said Tamerlane, "Can you teach this donkey to read and to write?"
"I can," replied Nasruddin, "but it will take about 25 years, and you'll need to pay a ton of wheat each year for tuition."
To Nasruddin's surprise, Tamerlane agreed.
"Have you lost your mind?" asked Nasruddin's friend. "You'll never teach that donkey to read and write!"
"That's true," said Nasruddin. "But in 25 years, the donkey will be dead, or I'll be dead, or the emperor will be dead. And in the meantime, I'll enjoy the use of a donkey plus a ton of wheat every year."
Inspired by: Mulla's Donkey and Other Friends by Mehdi Nakosteen
Notes: This story is on p. 11 of the book. Nakosteen does not tell this story about Tamerlane; he uses just a generic "someone" instead with Nasruddin's wife as the questioner, but I switched it to Nasruddin in Tamerlane's court.
This story became popular in Europe, as in this fable by Abstemius: Asinus et Grammaticus. This is an illustration from Sebastian Brant's Aesop.