A man says to his friend:
"I have three sons; I want you to figure out their ages from the following clues:
1) The sum of their ages is 13.
2) The product of their ages is the same as your age."
"Well, I would need more clues than that."
"OK, here is the third clue: my oldest son went to visit our neighbors' children."
"OK, now I have enough clues."
What are the ages?
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)