Suppose 8 marbles look identical, but once marble is slightly heavier than the others. Using only a balance scale, give a step by step "recipe" that will identify the heavier marble in exactly two weighting?
Please and Thanks!!
2007-08-27 12:48:47 · 2 answers · asked by Ronald K 1 in Science & Mathematics ➔ Mathematics
1. weigh any 2 groups of 3
2. a. If the two groups are equal weigh the remaining 2 marbles to find the heavier
2. b. If one group is heavier, weigh any two from that group.
2. b. 1 If one is heavier it's the heavy one
2. b. 2 If they balance, the remaining one is the heavy one.
2007-08-27 13:09:12 · answer #1 · answered by Helmut 7 · 0⤊ 1⤋
If I may give a hint: the trick is that there are three groups - marbles on one side, marbles on the other, and marbles not on the scale at all - and three possibilities - scale tipping right, tipping left, and balanced. From that you should be able to solve the puzzle.
2007-08-27 12:59:11 · answer #2 · answered by peri_renna 3 · 1⤊ 0⤋