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Mathematical form of mascot
(1) According to the meaning of the question, this is called classical probability.

The events involved in the experiment are five selected from eight mascots, and * * * has the result of C 8 5.

Select five events that meet the requirements to form a complete "Olympic mascot". * * There are C 2 1 C 3 1 results.

∴ The probability that the five selected animals just form a complete "Olympic mascot" P= C 12? C 13 C 58 = 6 56 = 3 28。

(2) If the score is expressed by the meaning of the question, the value of ξ is 100, 80, 60, 40.

According to the probability formula of classical probability and mutually exclusive events's probability formula.

P(ξ= 100)= C 12? C 13 C 58 = 3 28;

P(ξ=80)= C 23 ( C 22? C 13 + C 12? C 23 )+ C 33? (C 22+C 23)C 58 = 3 1 56; P(ξ=60)= C 13 ( C 22? C 23 + C 12? C 33 )+ C 23? C 33 C 58 = 18 56 = 9 28;

P(ξ=40)= C 22? C 33 C 58 = 1 56。

The ∴ξdistribution list is

∴ Eξ= 300 28 + 2480 56 + 540 28 + 40 56 =75。