10 test tubes, only a toxic, can only try again, will need at least a few mice?
This last question is another question a puzzle, then how did not find association of these two questions.
Think about a change in thinking give an answer,
Mixing tube, only N mice, the N maximum number of unique test tube 1, the N-1 with each other a total tube can express the N + (N-1) and the other co + (N-2 ) the second and the other co-+ ...... + 1
This expression is N * N- (N + 1) * N / 2> = 10
In fact, do not evaluate the expression 4 + 2 + 3 + 1 = 10
My answer is a minimum of four
There are other problem-solving ideas it?
Reproduced in: https: //www.cnblogs.com/jamesldj/p/3334632.html