Question for May 30, 2008

[jsteinb95]

It's been a while since we did a question of the day.....

Here it is;

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?



all correct answers will receive 10,000 credits. PM me your answers!

[jsteinb95]

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.