There are 9 cubic blocks marked with different numbers. 5 of them are blue and the
rest are pink. Maggie puts all the blocks in a row. Find the number of permutations if no
pink blocks are put next to each other.
Maths F5 (Permutation) 1題.
2012-09-10 6:17 am
回答 (1)
2012-09-10 7:09 am
✔ 最佳答案
B : blue block_ : space
Step 1 : Put the 5 blue blocks in a row [P(5,5)] : _B_B_B_B_B_
Step 2 : Put the 4 pink blocks in 4 of the 6 spaces "_" [P(6,4)].
Number of permutations
= P(5,5) x P(6,4)
= 5! x (6!/2!)
= 120 x 360
= 43200
參考: micatkie
收錄日期: 2021-04-13 18:58:00
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