20!/15!5!15!/11!4! eching

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

Baholash

$$21162960$$

Yechim qadamlari

20 ning faktoriali 2432902008176640000 ga teng.

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

15 ning faktoriali 1307674368000 ga teng.

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

5 ning faktoriali 120 ga teng.

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

156920924160000 hosil qilish uchun 1307674368000 va 120 ni ko'paytirish.

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

15504 ni olish uchun 2432902008176640000 ni 156920924160000 ga bo‘ling.

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

15 ning faktoriali 1307674368000 ga teng.

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

11 ning faktoriali 39916800 ga teng.

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

4 ning faktoriali 24 ga teng.

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

958003200 hosil qilish uchun 39916800 va 24 ni ko'paytirish.

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

1365 ni olish uchun 1307674368000 ni 958003200 ga bo‘ling.

$$15504\times 1365$$

21162960 hosil qilish uchun 15504 va 1365 ni ko'paytirish.

$$21162960$$

Omil

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