4/10
We can break it up into its factors
4 = 2 x 2
10 = 2 x 5
So then:
[tex]\sf{ \frac{4}{10} = \frac{2\times2}{2\times5}}[/tex]
And if we remove the 2 from the numerator and denominator we are left with your answer which is:
[tex]\boxed{\bf{\frac{2}{5}}}[/tex]
