Extremely Difficult Puzzle Questions 5, Extremely Difficult Puzzle Questions

A scheme was made:

The 12 table tennis balls are divided into 3 groups (Group A, Group B, Group C), with 4 pieces in each group.

Each ball is named A1, A2, A3, A4, B1 ......

Compare group A and group B on the scales first, if they are the same, the abnormal balls are in group C, and the next two times on the scale will judge the four balls in group C, which is very easy and will not be detailed.

If there is an imbalance between groups A and B, the anomalous balls are in both groups. The group that may have light balls (pan up) is named Group A, the group that may have heavy balls (pan down) is named Group B, and Group C is standard balls.

After that, the scales are loaded a second time: three standard balls and one ball (A1) in the tray on the left, and two balls (A2, A3) and two balls (B1, B2) in the tray on the right. There are three things that can happen after that:

The first case -

If the weighing pan is balanced, it means that there is a heavy ball in B3 or B4 outside the scale, or A4 is a light ball. In this case, the third time on the scale: compare B3 and B4, if balanced, then A4 outside the scale is a light ball, if not, then which weighing pan sinks, the one above it is a heavy ball.

Because Group B is a heavy ball suspect group, there can be no light ones).

The second case-

If the right disc of the scale rises, it means that there is a light ball in A3 and A4 in the right disc, [because there is no ball in Group B (heavy ball suspect group) in the left disc, so once the right disc rises, it must be light in A3 and A4], and the third time on the scale will judge both of them. (easy, not detailed).

The third case -

If the right disc of the scale drops, it means that there is a heavy ball in b1 and b2 in the right handicap, or a1 in the left handicap is a light ball. In this case, the third time on the scale: weigh B1 and B2, if balanced, then the scale outside A1 is a light ball, if not balanced, then which weighing pan sinks, the ball on the plate is a heavy ball.

It's not easy, probably. It took about two and a half hours, and it became clear to me after trying out the possibility of putting different groups of balls together. I look forward to everyone checking the results.

If the landlord has other good methods, please tell me, this method is very troublesome. ]

Take out 10, put 5 on each side (the first time), if the balance is balanced, put the remaining two on the first scale (twice), if it is not balanced, take out 4 on the heavy side, put 2 on one side (the second time), if balanced, then it is the remaining one (three times), if it is not balanced, take out the heavy side, and you will know it (also three times).

Again, take out 8 for the first time.

Hehe, I'm sorry, it seems like it took me less than 5 minutes.

Divide into three portions. 1。By placing two of the three parts on the scale, you can determine which of the three parts is abnormal.

2。Divide the anomalous one into two parts and find out which one has the anomaly.

3。Compare the two, the balance is tilted to that side, and that one is abnormal.

First of all, the scales have to be flat.

1. Add balls to both sides of the scale at the same time one by one (slowly).

When the imbalance is found, take out the last two (one must be abnormal) numbered 1 and 22, take one of the remaining 10, and weigh it once with the ball No. 1 and 2, and the unbalanced one (one of 1 and 2) is it.

Two by two until they are found to be unequal. At this point, everything else is normal. Pick out one of those two and weigh one normally, if it is the same weight, it means that the remaining one is abnormal.

Divide the balance in half at both ends, take the heavy end, and then divide the weight at the end in half.

When you get to the remaining three, you can take one good one and try it one by one.

The average score is three, and it's correct to think about it according to this division, and I only suggest that this is boring.

I only know the first 4 4 scales.

How? It's really hard!