Lahenda 20!/15!5!15!/11!4!

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

Arvuta

$$21162960$$

Lahenduse etapid

20 faktoriaal on 2432902008176640000.

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

15 faktoriaal on 1307674368000.

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

5 faktoriaal on 120.

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

Korrutage 1307674368000 ja 120, et leida 156920924160000.

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

Jagage 2432902008176640000 väärtusega 156920924160000, et leida 15504.

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

15 faktoriaal on 1307674368000.

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

11 faktoriaal on 39916800.

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

4 faktoriaal on 24.

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

Korrutage 39916800 ja 24, et leida 958003200.

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

Jagage 1307674368000 väärtusega 958003200, et leida 1365.

$$15504\times 1365$$

Korrutage 15504 ja 1365, et leida 21162960.

$$21162960$$

Lahuta teguriteks

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