Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.

can you solve this riddle? first correct annswer gets 10pts!?

Four people are on one side of a bridge that they need to cross. It is dark, there are holes in the bridge surface, and they only have 1 flashlight which must travel with them as they cross. To add to their troubles, the bridge will only support two people at a time

Person 1- can walk across in 1 min

Person 2- has a limp and takes 2 min

Person 3- has a sprained ankle takes 5 min

Person 4- has a cast on his legs and takes 10 min

No matter how fast a person can cross, he must for his companion. If #1 goes with #2 it takes 2 min to cross. If #2 goes with #4 it will take 10 min. The flashlight cannot be thrown, instead it must be carried and delivered from person to person(someone has to go back and forth). The 4 people are trying to make it across in the fastest time to make an important appointment.

What is the fastest time in min. for them to cross the bridge?

explain how you got it!

GOOD LUCK!

Update:

it's less than 19 min....

Update 2:

once again...it is NOT 19 min

16 Answers

Relevance
  • 1 decade ago
    Favorite Answer

    Person 1 and 2 go across = 2

    One goes back = 3

    3 and 4 go across = 13

    2 goes back = 15

    1 and 2 go across =17 minutes total

  • Anonymous
    1 decade ago

    sorry, but this can be answered with the simplest of solutions:

    Trip 1: Person 1 w/ Person 4 across = 10 min

    Trip 2: Person 1 back = 1 min

    Trip 3: Person 1 w/ Person 3 across = 5 min

    Trip 4: Person 1 back = 1 min

    Trip 5: Person 1 w/ Person 2 = 2 min.

    10 + 1 + 5 + 1 + 2 = 19 min.

    i got it by simple reasoning

    Source(s): me
  • 1 decade ago

    i believe its 19 mins...

    person 1 crosses with person 4 and the person 1 comes back for a total of 11 mins

    person 1 then crosses with person 3 and then person 1 comes back for a total of 6 min

    person 1 then cross with person 2 for a total of 2 mins

    11+6+2 = 19

    person 1 always has the flashlight

  • 1 decade ago

    first person 1 goes w/ person 4. that takes 10 mins. then person 1 goes back and give it to person 2. that makes 11 mins. then person 2 goes w/ 3. that takes 16 mins.person 2 goes back. that makes 18 mins. He goes with person 1. across. THAT MAKES 20

    I cant think of a faster way!

    I used logic

  • How do you think about the answers? You can sign in to vote the answer.
  • Anonymous
    1 decade ago

    19 minutes!!

    # 1 and # 4 go over = 10 minutes

    # 1 comes back = 1

    #1 and # 3 go over = 5

    #1 comes back = 1

    #1 and #2 go over = 2

    10+ 1 +5 + 1 +2 = 19 minutes!!

  • 1 decade ago

    person 1 and 2 go which makes 2 minutes. then person one goes back to give them the flashlight and goes back with person number three with is 5 minutes. that makes 8 minutes so far. then person one goes back to give number 5 the flashlight and comes back with them which makes 11 minutes. therefore, the time is 19 minutes.

  • 1 decade ago

    6 Minuets person #1 gives each person a piggy back ride across the bridge.

  • They all skipped the appointment, lost their jobs, and were found in the river under the bridge because they all tried to get across together.

  • ?
    Lv 4
    5 years ago

    the pony is termed Friday! For the guy who already replied, Friday could desire to be captialized so technically he's faulty! See that.....in case you anwered that at school, factors could be deducted for no longer answering in suitable variety.... Gimme da darn factors!!!!!!!! So then, you positioned up that 2 wrongs make a suitable?

  • 1 decade ago

    17 mins

    2 & 1 go together, 1 goes back =3mins

    10& 5 go together, 2goes back = 12mins

    2 & 1 go together=2mins

    3+12+2=17mins

    Edited: Hope it's right now.

Still have questions? Get your answers by asking now.