Try the following GMAT Quantitative Reasoning question on manipulating and simplifying expressions with radical terms.
Question 67:
$\dfrac{(\sqrt{2})(\sqrt{5})}{(\sqrt{7}\sqrt{2}\sqrt{5})(\sqrt{7}+\sqrt{2}+\sqrt{5})}=$

$\quad 2$

$\quad 1$

$\quad \dfrac{1}{2}$

$\quad \dfrac{1}{2}$

$\quad 1$