Answer
False
Work Step by Step
$\dfrac{10}{25}$ is not yet reduced to lowest terms since the numerator and the denominator still have a common factor of $5$.
Note that:
$\require{cancel}
\\\dfrac{10}{25}
\\=\dfrac{5(2)}{5(5)}
\\=\dfrac{\cancel{5}(2)}{\cancel{5}(5)}
\\= \dfrac{2}{5}$
Thus, the given statement is false.