1 Ball is heavier of of 8 balls, can you find which one?

You have 8 balls all of the same size. 7 of them weigh the same, and one of them weighs slightly more.

How can you find the ball that is heavier by using a balance and only two weighings?

 

Share
SherlockHolmes Expert Asked on 24th August 2015 in Interview Puzzles.
Add Comment

  • 1 Answer(s)
    Best answer

    Divide the balls into the following groups: (1,2,3),(4,5,6),(7,8)

    Step 1.
    Weigh (1,2,3) against (4,5,6)

    Two possible outcomes:
    The two groups are equally heavy. (Case A)
    One of these groups is heavier than the other. (Case B)

    Case A
    Weigh 7 against 8.  Now you have identified the heavier ball in 2 weighing.

    Case B

    Take the heavier group (assume it to be (1,2,3)), take any two balls and weigh them against each other. Either one of these is heavier else the third ball is.

    Detective Expert Answered on 24th August 2015.
    Add Comment
  • Your Answer

    By posting your answer, you agree to the privacy policy and terms of service.
  • More puzzles to try-

  • Tags