Apple Seeds
A man was idling in the street, bored when he saw a man selling apples close by.
He approached the man, and asked, "How much do these apples cost?". The vendor replied, "An apple costs $1 and an apple seed costs $2.". Confused, the man asked, "Why are you selling the seeds? and why are they so expensive?". The vendor said, "Apple seeds are actually known to make you so much times smarter. Why don't you try them?". Skeptical, the man handed over $4 and purchased two seeds. As he walked a little bit away, and started chewing them, he realized that he could have just bought an apple and eaten those seeds. Hurrying back to the vendor, he asked, "Don't you realize that people could just buy an apple and eat those seeds instead of buying seeds separately?". The vendor smiled, and said, "See? I told you that you'll become smarter!"