A Riddle

So Wednesday night I was sitting in computer lab staring at my book just getting used to the monotony which is translating binary. As I continue working I stumble upon a riddle in my book. I am the type of person who enjoys puzzles and riddles. I love to use the basic information given to solve a puzzle. I thought back to when I was little and I had a book called Stories To Solve. I can remember reading through it and solving each puzzle, but once you knew the answer you loose the excitement. But knowing the answer doesn’t take away from the fun of knowing riddles. So today I’d like to share a new riddle with you.

So here it goes. There are four miners in a mine shaft and one miner’s lamp. The tunnel is only big enough for two miners to walk through at a time, however the miners can walk the tunnel alone. But if they go through the tunnel they must have the miner’s lamp. They are trying to get out of the mine in 15 minutes. The first miner takes 1 minute, the second 2, the third 4, and the fourth 8. When the miners are walking together they walk at the speed of the slower walker. How did they walk through the tunnel so they all could make it out in 15 minutes ?

I hope you have fun and there is a real ( non silly) answer.  If you are stumped I’ll put the answer in the comments area.