Physics teacher: “It was only after an apple fell on Newton’s head that he discovered gravity. Now children, tell me why is there no gravity on the moon?”
One of the students replied: “Simple Ma’am, there are no apple trees on the moon.”

Rajesh, who lives in the city, asks a farmer: “Why doesn’t this cow have any horns?”
Farmer: “There are many reasons: Some are born without horns, some shed their horns, some have their horns taken out. But as for this cow here, the reason is simple. This cow is a horse.”