#### Answer

$\frac{4}{35}$

#### Work Step by Step

To write a fraction in simplest terms divide the numerator and denominator by the greatest common factor.
$24=\underline2\times2\times2\times\underline3$
$210=\underline2\times\underline3\times5\times7$
$GCF=2\times3=6$
$\frac{24}{210}=\frac{24\div6}{210\div6}=\frac{4}{35}$