Light Weight is the 6th puzzle from The Curious Village. It where been suggested by Marco of St. Mystere.
Here we have eight small weights that all look the same. However, one of the weights in the group is slightly lighter than the rest. Using this scale two times, you can find out which of these weights is lighter than the rest. So, which weight is the light one?
The lightest weight changes each time. To find the correct weight, weigh any three weights on one side against another three weights. If neither side is lighter, weigh the remaining two weights to find your answer.
If one side is lighter, one of the three weights on the light side is the lightest weight. Weigh two of those three weights against each other. If one side is lighter, you have your answer. If neither side is lighter, than the weight left off the scale is the lightest.