How long will it take?

A German backpacker tourists are enjoying a holiday in the hinterland missisipi. He decided to walk.

When he about to continue the journey in a village, the sky looks a bit gloomy. It seems the rain will fall in a moment. Tourists are in doubt whether he should continue or suspend journey.

He asked in a cotton farmer. "Sir, how long can we reach the next village?"

Cotton farmers that are still not turned a bit. The backpacker wait for the answer but the results are useless.

Chapfallenly, the tourists move away. When he was just walking around thirty meters, the farmers called him. The tourists were forced to return.

"Around twenty minutes duration," the exclamation farmers.

Thank you, "reply the tourists." But why you are silent since earlier? "

"What can I answer your question Son, if I had not see how fast you walk ?"
that the cotton farmers.