Protecting Innovation, Technology, and the Arts

In celebration of Durga Puja

 

In celebration of the Tri-State Durga Puja, here’s a riddle for you:

Volcano

It is a dark, moonless night when a volcano violently erupts. A group of four campers see the eruption, grab a flashlight, and run for their lives. While running, the first camper breaks his leg, the second camper sprains her ankle, and the third camper loses a shoe. After running for a bit, the campers come across a ravine spanned by a rope footbridge. Luckily, if the campers make it across the bridge, the flowing lava will enter the ravine and the campers will be safe. Unluckily, the bridge can only support two people at a time, and since it is dark, they must use the flashlight to cross. Therefore, after two people cross safely, one person must return to get another.

 

The camper with the broken leg needs ten minutes to cross the bridge, the camper with the sprained ankle needs five minutes to cross the bridge, and the one-shoed camper needs two minutes to cross the bridge. The final camper can make it across the bridge in one minute. Thus, if the fourth camper and the camper with the sprained ankle cross together, they take five minutes. Unfortunately, the final camper estimates that the lava will be upon the ravine in seventeen minutes, destroying the bridge. Can all four campers make it the entire way across the bridge without throwing the flashlight or crossing (even partially) in the dark without the flashlight?

 

For the answer, scroll down…

 

 

 

 

 

 

 

 

 

 

 

1. The fourth camper and the camper without a shoe cross the bridge = 2 minutes; 2 minutes total

2. The fourth camper returns = 1 minute; 3 minutes total

3. The camper with the broken leg and the camper with the sprained ankle cross the bridge = 10 minutes; 13 minutes total

4. The one-shoed camper returns = 2 minutes; 15 minutes total

5. The fourth camper and the one-shoed camper cross = 2 minutes; 17 minutes total

6. Everyone has some key lime pie and celebrates.