Question

You have eight 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?

Answer 1

To identify the heavier ball out of eight, divide them into groups and use a balance scale for elimination. After two weighings, the heavier ball can be effectively identified.

Step-by-step explanation:

To find the heavier ball out of eight balls with only two weighings, you could take the following steps using a balance:

1. Divide the eight balls into three groups: two groups of three balls each, and one group of two balls.
2. Place one group of three balls on each side of the balance. If one side is heavier, proceed to step 3 with the heavier group. If both sides are equal, the heavier ball must be in the group of two, which you proceed with in step 4.
3. Take the three balls from the heavier side of the scale. Choose any two of these and place one on each side of the balance. If one side is heavier, you've found the heavier ball. If they balance out, the third ball that was not on the scale is the heavier one.
4. If it was a group of two balls, simply place them on the balance. The side that goes down is the heavier ball.

This process efficiently identifies the heavier ball by eliminating the balls that are of equal weight and focusing on the ones that have shown a difference in weight on the balance.