i dont understand how 5!/2!3! is 10??
$$\frac{5!}{2!3!}\\\\ =\frac{1*2*3*4*5}{1*2\;*\;1*2*3}\\\\ =\frac{2*3*4*5}{2\;*\;2*3}\\\\ =\frac{\not{2}*\not{3}*4*5}{2\;*\;\not{2}*\not{3}}\\\\ =\frac{\not{4}^2*5}{\not{2}}\\\\ =2*5\\\\ =10$$
5!/2!3 =
120/(2(6)) =
120/12 =
10