10 Marbles Riddle

Here is an interesting riddle involving 12 marbles and a balance scale.

10 marbles riddle.

1 bag contains 9 ounce marbles. You don t know which is which. In this case you know that the different marble is 9 10 or 11 and that that marble is heavy. If a black marble comes out you know that has to be the black marbles box so you put the black label on it.

Since you know that the box is labeled incorrectly it must have all black marbles or all white marbles. But you have to follow the following rules. If not the heavier one is the heavy marble. 9 bags contain 10 ounce marbles.

The remaining marble is slightly heavier than the others. Proceed as in the step above but the marble you re looking for is the light one. 3 9 10 11 is light. The scales are of the old balance variety.

If they balance 11 is the heavy marble. In other words you get to take 2 measurements or comparisons here. 2 9 10 11 is heavy. You are given a set of scales and 12 marbles.

You can use a scale you can use an empty sack. Simply weigh 9 against 10. With a scale you have to figure out how to figure out which bag contains the 9 ounce marbles. 1 you have 9 marbles as seen.

In any case on to the riddle. There are 10 bags of marbles. The one labeled both. 3 you are allowed to use set the scale twice in total.