Riddles: Band on a Bridge

Posted on 07. Sep, 2009 by Jake in brain teasers

More puzzles for ya today…

Band across the Bridge
Four members of a band are walking to a night concert. They decide to take a shortcut, but must cross a bridge. Luckily they have one flashlight. Because of the varying size of their instruments, it takes each member a different amount of time to cross the bridge – it takes the first person one minute, the second person two minutes, the third person five minutes and the fourth person ten minutes. They must cross the bridge in pairs, travelling at the slower speed so if the one minute person went with the ten minute person, it would take a total of ten minutes. Since there is only one flashlight, one person must come back across the bridge, then another pair can cross. They only have 17 minutes to cross the bridge and still get to the concert on time. What order should they cross to get everyone across and get to the concert?

Answer: First, the one minute person and the two minute person must cross the bridge, for a total of two minutes. Then the one minute person should come back with flashlight – total of three minutes. The five minute person and the ten minute person cross together next, making the total thirteen minutes. Now the two minute person goes back and (total now fifteen minutes) and gets the one minute person and they cross together bringing the total to seventeen minutes.

Weighing for Godot
Godot was recently hired by a local shipping factory and was struggling to read the labels. He could read the weights, but not the addresses. Before he could decipher the text, a pair of brothers walked in and declared that some of the six boxes currently sitting on the counter belonged to them. Godot asked if they knew which ones were their packages, but the first brother only knew that his packages weighed twice what his brother’s two did. If the packages weighed 15, 16, 18, 19, 20, and 31 pounds, which packages did Godot hand them?