
There are few things less fun than having your car conk out in the middle of a rural area when it’s dark and cloudy (even if you do have AAA roadside assistance). Here’s a puzzle about four women who get stuck in that situation:
Four women are in a car that runs out of gas very late one night. For safety’s sake, they decide to abandon the car as a group, since they have only one flashlight between them. They see a light on at a nearby farmhouse, but none of the women want to approach it alone.
In order to reach the house, they must make their way across a creaky old footbridge that will support the weight of no more than two of them at a time. The women must carry the flashlight while crossing the bridge, because it’s dark and very difficult to see.
Andrea is the slowest; it takes her ten minutes to traverse the bridge. Barbara can do it in five minutes, Carolyn can make it in two minutes, and speedy Delilah can cross in only one minute. Of course, if two of the women cross simultaneously, they do so at the slower woman’s pace.
Can you figure out a way to get all four women across the bridge in only 17 minutes?
HERE is the solution.
smart
posted by Matt on 10-22-2008 at 9:16 am
fun :)
First time through I had Delilah shuttling back solo (19 min). Consolidating A&B saved me the extra time when you’ve got C or D to bring the flashlight back across…
Of course, Andrea can just wait in the car :)
posted by josh on 10-22-2008 at 9:41 am
I was thinking the same way Josh was. Had a bit of a duh moment when I saw the answer.
Thanks for the brain workout!
posted by nutmeag on 10-22-2008 at 10:01 am
Or, they can wait until daylight when they don’t need the flashlight.
posted by SlackJack on 10-22-2008 at 3:51 pm
Dumbest riddle ever!
They can do it in ten minutes.
Send Delilah and Andrea together, Andrea holding the flashlight to point it back at her friends to light the way.
When she gets to the other side, one of the next two starts (while Andrea humbly putters along) and then the next one. Never more than two on the bridge, ten minutes total time.
Oh… it’s not supposed to reflect reality? Sorry.
posted by tiddo on 10-23-2008 at 1:44 pm