Do you want to ask, "according to a certain rule, how many students line up?" This kind of problem?

If so, it can be said that this is very useful.

The basic idea of permutation and combination in mathematics has been exercised, which will be very useful in learning binomial decomposition, statistics, probability and sequence problems.

Learning binomial is the basis of many advanced mathematics, including Taylor expansion, infinite series and so on. Learning statistics and probability is an introduction to a series of sciences such as data processing, matrix operation and computer big data, and it is also the basis for learning thermophysics, experimental physics and chemistry.

Therefore, it is necessary to use this knowledge in future study, just as the problem of chickens and rabbits in the same cage is the bud of binary equation. If you want to ask what's the use of learning so much knowledge, then I say that those jobs that don't need thinking will eventually be replaced by robots, and they don't want to be eliminated by the times. Learning knowledge is useful.

There is no useless knowledge, which is the law of the scientific community.