hitunglah permutasian pencacahan dari a. P (20,17) b. P (15,13)

a) P (20,17) = 20! /(20-17)!
= 20! / 13!
= 20 × 19 × 18 × 17 × 16 × 15 × 14 × 13!/13!
b) P ( 15 , 13) = 15! / (15-13)!
= 15! / 2!
= 15 × 14 × 13 × 12 × 11 × 10 × 9 × 8 × 7 × 6 × 5 × 4 × 3
= .....

Kelas 10 Matematika
Bab Peluang

^ = pangkat

1] 20P17
= 20 ! / (20 - 17) !
= 20 . 19 . 18 . 17 . 16 . 15 . 14 . 13 . 12 . 11 . 10 . 9 . 8 . 7 . 6 . 5 . 4 . 3 ! / 3 !
= 20 . 19 . 18 . 17 . 16 . 15 . 14 . 13 . 12 . 11 . 10 . 9 . 8 . 7 . 6 . 5 . 4
= 4,05483668 x 10^17

2] 15P13
= 15 ! / (15 - 13) !
= 15 . 14 . 13 . 12 . 11 . 10 . 9 . 8 . 7 . 6 . 5 . 4 . 3 . 2 ! / 2 !
= 15 . 14 . 13 . 12 . 11 . 10 . 9 . 8 . 7 . 6 . 5 . 4 . 3
= 653.837.184.000