Required Mathematical Intelligence

Chapter 70 Four Children Race
The four children A, B, C, and D raced on the playground, and they raced four times in total—Among them, A was faster than B three times, B was faster than C three times, and C was faster than D three times.Perhaps everyone will think that D must be the slowest.But in fact, in these four times, D is also faster than A three times.

What kind of situation is this?

[Answer: If the rankings of the four times are:
1. A, B, C, D;

2. B, C, D, A;

3. C, D, A, B;

4. D, A, B, C.

在1、3、4次A比B快，在1、2、4次B比C快，在1、2、3次C比D快，而在2、3、4次D就比A快。]
(End of this chapter)