helpppppp please, i am stuck

26C5/67C5 =

$\begin{array}{rcll} 26C5 &=& \frac{26!}{5!\cdot (26-5)! } \\ &=& \frac{26!}{5!\cdot 21! } \\ &=& \frac{21!\cdot 22\cdot 23\cdot 24\cdot 25\cdot 26}{5!\cdot 21! } \\ &=& \frac{22\cdot 23\cdot 24\cdot 25\cdot 26}{5! } \\\\ 67C5 &=& \frac{67!}{5!\cdot (67-5)! } \\ &=& \frac{67!}{5!\cdot 62! } \\ &=& \frac{62!\cdot 63\cdot 64\cdot 65\cdot 66\cdot 67}{5!\cdot 62! } \\ &=& \frac{63\cdot 64\cdot 65\cdot 66\cdot 67}{5! } \\\\ \frac{ 26C5 } {67C5} &=& \dfrac{ \frac{22\cdot 23\cdot 24\cdot 25\cdot 26}{5!} } { \frac{63\cdot 64\cdot 65\cdot 66\cdot 67}{5!} }\\ &=& \frac{22\cdot 23\cdot 24\cdot 25\cdot 26}{5!} \cdot \frac{5! }{63\cdot 64\cdot 65\cdot 66\cdot 67}\\ &=& \frac{22\cdot 23\cdot 24\cdot 25\cdot 26}{63\cdot 64\cdot 65\cdot 66\cdot 67}\\ &=& \frac{7893600 } { 1158917760 } \\ &=& \frac{ 115 } { 16884 } \\ &=& 0.00681118218 \end{array}$

26C5/67C5 =

$\begin{array}{rcll} \frac{ 26C5 } {67C5} &=& \frac{ \binom{26}{5} }{ \binom{67}{5} } \\\\ &=& \frac{ \frac{26}{5} \cdot \frac{25}{4}\cdot \frac{24}{3}\cdot \frac{23}{2}\cdot \frac{22}{1} }{ \frac{67}{5} \cdot \frac{66}{4}\cdot \frac{65}{3}\cdot \frac{64}{2}\cdot \frac{63}{1} } \\\\ &=& \dfrac{ 26 \cdot 25 \cdot 24 \cdot 23 \cdot 22 } { 67 \cdot 66 \cdot 65 \cdot 64 \cdot 63 } \\\\ &=& \dfrac{7893600 } { 1158917760 } \\\\ &=& \dfrac{ 115 } { 16884 } \\\\ &=& 0.00681118218 \end{array}$

I didn't understand that at all.