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Multiplication principle

Classical problem

~ ~ belongs to the category of probability

Is the fourth power of 10 = 10000.

(multiplication principle: to do one thing, you need to divide it into n steps and be the first.

There are different methods for step m 1, different methods for step m2, different methods for step n and different methods for step n.

N=m 1m2m3…mn

Different methods.

)