All the students attend the competition and exactly 2 freshmen win prizes.
4C3*14C3*6!
4C4*14C2*4!
4C2*14C4*6!
4C1*14C5*6!
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The number of orders in which all the students attend the competition and exactly 2 freshmen win prizes =4C2×14C4×6!
All students attend the competition and the winners are exactly 3 freshmen and 3 sophomores.
All students attend the competition and the winners are an equal number of freshmen, sophomores and juniors.
Solve the following.
130 students participate in an essay competition. If 26 students win prizes, find the percentage of winners.