Réitigh 20!/15!5!15!/11!4!

$$\frac{ 20 ! }{ 15 ! 5 ! } \frac{ 15 ! }{ 11 ! 4 ! }$$

Luacháil

$$21162960$$

Céimeanna Réitigh

Is é iolrán 20 ná 2432902008176640000.

$$\frac{2432902008176640000}{15!\times 5!}\times \frac{15!}{11!\times 4!}$$

Is é iolrán 15 ná 1307674368000.

$$\frac{2432902008176640000}{1307674368000\times 5!}\times \frac{15!}{11!\times 4!}$$

Is é iolrán 5 ná 120.

$$\frac{2432902008176640000}{1307674368000\times 120}\times \frac{15!}{11!\times 4!}$$

Méadaigh 1307674368000 agus 120 chun 156920924160000 a fháil.

$$\frac{2432902008176640000}{156920924160000}\times \frac{15!}{11!\times 4!}$$

Roinn 2432902008176640000 faoi 156920924160000 chun 15504 a fháil.

$$15504\times \frac{15!}{11!\times 4!}$$

Is é iolrán 15 ná 1307674368000.

$$15504\times \frac{1307674368000}{11!\times 4!}$$

Is é iolrán 11 ná 39916800.

$$15504\times \frac{1307674368000}{39916800\times 4!}$$

Is é iolrán 4 ná 24.

$$15504\times \frac{1307674368000}{39916800\times 24}$$

Méadaigh 39916800 agus 24 chun 958003200 a fháil.

$$15504\times \frac{1307674368000}{958003200}$$

Roinn 1307674368000 faoi 958003200 chun 1365 a fháil.

$$15504\times 1365$$

Méadaigh 15504 agus 1365 chun 21162960 a fháil.

$$21162960$$

Fachtóirigh

$$2^{4}\times 3^{2}\times 5\times 7\times 13\times 17\times 19$$