Solution:
Consider the complement of the original proposition, that is, the probability of pairing at most two shoes:
Choose 4 pairs from 5 pairs and use different methods C 10 4 (meaning C10, upper 4, the same below).
There are only two pairs of 4 shoes: C5 1 C5 1 * C4 2 * C21+0 (choose1pair from 5 pairs first, choose 2 pairs from the remaining 4 pairs, and choose1pair from each of the selected 2 pairs).
None of the four pairs of shoes can be matched: C5 4 * C21+0 (first, choose four pairs from five pairs, and choose one pair from each of the four pairs).
So the probability of pairing at most two shoes: p = (C51* c42 * C21+c54 * C21)/c104 = 8/21.
So the probability of the original proposition:1-8/21=13/21.
The probability is 13/2 1.
Ps: Why are you again? Besides, how did I miscalculate again ~
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