[tex]\frac{1}{\frac{5}{2} }[/tex]
You multiply [tex]\frac{2}{5}[/tex] to the numerator and the denominator to get rid of the fraction in the denominator.
[tex]\frac{1}{\frac{5}{2} }[/tex] × [tex]\frac{\frac{2}{5} }{\frac{2}{5} }[/tex]
= [tex]\frac{\frac{2}{5} }{1} =\frac{2}{5}[/tex]
