Remember:
Permutation means aranggement of objects in which order matters. To solve the permutations problem we need to used the formula which is:
Direction:
Solving the following permutations using the formula.
1.) P(8, 5)
- P(n, r) = n!/(n - r)!
- P(8, 5) = 8!/(8 - 5)!
- P(8, 5) = 8!/3!
- P(8, 5) = 8 × 7 × 6 × 5 × 4 × 3!/3!
- P(8, 5) = 8 × 7 × 6 × 5 × 4
- P(8, 5) = 6,720
∴ The permutation is 6,720.
2.) P(21, 7)
- P(n, r) = n!/(n - r)!
- P(21, 7) = 21!/(21 - 7)!
- P(21, 7) = 21!/14!
- P(21,7)=21×20×19×18×17×16×15×14!/14!
- P(21, 7) = 21×20×19×18×17×16×15
- P(21, 7) = 586,051,200
∴ The permutation is 586,051,200.
3.) P(30, 2)
- P(n, r) = n!/(n - r)!
- P(30, 2) = 30!/(30 - 2)!
- P(30, 2) = 30!/28!
- P(30, 2) = 30 × 29 × 28!/28!
- P(30, 2) = 30 × 29
- P(30, 2) = 870
∴ The permutation is 870.
4.) P(12, 5)
- P(n, r) = n!/(n - r)!
- P(12, 5) = 12!/(12 - 5)!
- P(12, 5) = 12!/7!
- P(12, 5) = 12 × 11 × 10 × 9 × 8 × 7!/7!
- P(12, 5) = 12 × 11 × 10 × 9 × 8
- P(12, 5) = 95,040
∴ The permutation is 95,040.
5.) P(15, 3)
- P(n, r) = n!/(n - r)!
- P(15, 3) = 15!/(15 - 3)!
- P(15, 3) = 15!/12!
- P(15, 3) = 15 × 14 × 13 × 12!/12!
- P(15, 3) = 15 × 14 × 13
- P(15, 3) = 2,730
∴ The permutation is 2,730.
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