|
Question 9623: Eight marbles look alike, but one is slightly heavier than the others. Using a balance scale, explain how you can determine the heavier one in exactly 2 weighings.
Answer by Earlsdon(6294)   (Show Source):
You can put this solution on YOUR website! Here's one way:
Take two of the marbles and put them to one side.
Put the remaining six marbles on the balance, three on each side. (Weighing # 1)
If they balance then you know that the heavier marble is on of the two marbles you put aside. Weigh these two to find the heavier marble.(Weighing # 2)
If the six marbles (three on a side) don't balance, then take the three that are on the heavy side, put one of these aside and weigh the other two. (Weighing # 2). If these balance, then you know that the one marble you put aside is the heavier one.
If they don't balance, then you have found the heavier marble on the balance.
|
|
|
| |
