Answer:
The answer is "[tex]7.21 \times 10^{37}[/tex]".
Step-by-step explanation:
[tex]\to ^{n}_{C_r}=\frac{n!}{r!(n-r)!}[/tex]
[tex]=^{66}_{C_{33}} \times ^{66}_{C_{22}} \times ^{55}_{C_{1}} \\\\=\frac{66!}{33! (66-33)!} \times \frac{66!}{22! (66-22)!} \times \frac{55!}{1! (55-1)!}\\\\=\frac{66!}{33! (33)!} \times \frac{66!}{22! (44)!} \times \frac{55!}{1! (54)!}\\\\=\frac{66!}{33! (33)!} \times \frac{66!}{22! (44)!} \times \frac{55\times 54!}{1! (54)!}\\\\=\frac{66!}{33! (33)!} \times \frac{66!}{22! (44)!} \times 55\\\\= 7219428434016265740 \times 182183167981760400\times 55\\\\[/tex]
[tex]= 7.21 \times 10^{18} \times 1.82\times10^{17}\times 55\\\\= 7.21 \times 10^{35} \times 1.82\times 55\\\\=721.721 \times 10^{35}\\\\=7.21\times 10^{37}[/tex]
