brain teaser

U2 has a concert that starts in 17 minutes and they must all cross a bridge to get there. All four men begin on the same side of the bridge. You must help them across to the other side. It is night. There is one flashlight. A maximum of two people can cross at one time. Any party who crosses, either 1 or 2 people, must have the flashlight with them.

The flashlight must be walked back and forth. It cannot be thrown and other tricks like that are not needed to solve the problem. The solution is simply a matter of allocating resources in a certain order. Each band member walks at a different speed. A pair must walk together at the rate of the slower man's pace:

Bono: 1 minute to cross
Edge: 2 minutes to cross
Adam: 5 minutes to cross
Larry: 10 minutes to cross

For example: if Bono and Larry walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Larry then returns with the flashlight, a total of 20 minutes have passed and you have failed the mission.

  1. 👍 0
  2. 👎 0
  3. 👁 245
  1. Bono (1) walks over with Edge (2), 2 minutes, Bono walks back, 1 minute (3 total), Larry (10) and Adam (5), walk across, 10 minutes (13 total), Edge Walks Back, 2 minutes (15 total), Edge and Bono walk back, 2 minutes (17 total)

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. science

    Suppose that the 1.3 km span of the golden gate bridge had no expansion joints. Calculate how much longer the bridge would be if the temperature of the bridge increases by 35 degrees celsious

    asked by Joey on March 1, 2013
  2. Physics

    The Golden Gate Bridge in San Francisco has a main span of length 1.28 km, one of the longest in the world. Imagine that a steel wire with this length and a cross-sectional area of 4.00 x 10-6 m^2 is laid on the bridge deck with

    asked by Anna on June 15, 2015
  3. physics

    a train 100m long is to cross a river bridge of length 800m. what time it take to cross the bridge ?velocity of train is 36km/h.

    asked by akanksha on June 7, 2014
  4. economics

    2. A company is considering building a bridge across a river. The bridge would cost $2 million to build and nothing to maintain. The following table shows the company¡¯s anticipated demand over the lifetime of the bridge: Price

    asked by tianbai on November 13, 2007
  5. econ.

    2. A company is considering building a bridge across a river. The bridge would cost $2 million to build and nothing to maintain. The following table shows the company¡¯s anticipated demand over the lifetime of the bridge: Price

    asked by fred on June 11, 2011
  1. Math-soh cah toa

    A bridge is 140m long.From the ends of the bridge, the angles of depression of a point on the river under the bridge is 41° and 48°. How high is the bridge above the river to the nearest meter. ( I know the answer is 68m, I just

    asked by Kennedy on April 7, 2016
  2. physics

    A 200m long train crosses a 400m long bridge with a speed of 36km/hr . Calculate the time taken by train to cross the bridge? plz give me the answer with explaination

    asked by Maihul on July 6, 2012
  3. Vocab

    My mom told me not to worry. We will cross that bridge when we come to it. A. Hyperbole B. Simile C. Metaphor D. Cliche D?

    asked by Alex on November 12, 2015
  4. English

    1. The concert is over. 2. The concert is finished. 3. The concert ended. 4. The concert finished. [Are they the same in meaning? Can we use all the sentences? Which ones are unacceptable? Do you have some more similar

    asked by rfvv on April 5, 2018
  5. world history

    What impact did the Concert of Europe have on Europe? 1.) The Concert of Europe sought to establish a unified trading partnership to promote unity and eliminate future wars. 2.) The Concert of Europe sought to eradicate monarchies

    asked by kayla on February 23, 2018
  6. algebra

    You live near a bridge that goes over a river. The underside of the bridge is an arch that can be modeled with the function y=-0.000475x^2+0.851x, where x and y are in feet. How high above the river is the bridge(the top of the

    asked by LEE on October 20, 2012

You can view more similar questions or ask a new question.