12 Marbles Riddle

The one labeled both.

12 marbles riddle. 12 marbles problem. How can you find the heavier marble by using a balance scale only thrice. You don t know if that one is heavier or lighter. So another perfectly valid solution to the 12 marbles puzzle might even be.

2v2 8 xy 1v1 0 z 3v3 2 xy 1v1 1 z 1v1 0 which requires only two weights in one third of the cases. Weigh 7 vs 8 if they balance then 4 is the odd light ball or the heaviest of 7 vs 8 is the odd heavy ball. You have 12 marbles. So that the plan can be followed let us number the marbles from 1 to 12.

What is the minimum number of weighings required to do this. If 1 2 5 vs 3 6 12 balances then either 4 is the odd light ball or 7 or 8 is the odd heavy ball. There are two possibilities. The scales are of the old balance variety.

You can perform up to a maximum of three weighings to find out which marble has the different weight and if it is heavier or lighter than the others. 12 marbles written on 3 23 am by vja students you have twelve marbles. If 3 6 12 is heavy then either 6 is the odd heavy ball or 1 or 2 is the odd light ball. One of the marbles is heavier in weight than the rest.

For the first weighing let us put on the left pan marbles 1 2 3 4 and on the right pan marbles 5 6 7 8. You have twelve marbles that are identical in size shape and color. In general if you have n weights at your disposal you can solve the puzzle up to 3 n marbles included. If a black marble comes out you know that has to be the black marbles box so you put the black label on it.

You have a balance scale. Pick 2 groups and use the scale to determine which group contains. They all weigh the same except one. Since you know that the box is labeled incorrectly it must have all black marbles or all white marbles.

Split the marbles into 3 groups with 4 marbles each. You are given a set of scales and 12 marbles. That is a small dish hangs from each end of a rod that is balanced in the middle. Either they balance or they don t.