Answer
$\frac{7}{11ab^{2}}$
Work Step by Step
To write the fraction in its simplest form, find the greatest common factor of the numerator and denominator.
$ \frac{245ab}{385a^{2}b^{3}}=\frac{35ab (7)}{35ab (11ab^{2})}$
Cancel out the greatest common factor
$\frac{35ab (7)}{35ab (11ab^{2})}= \frac{7}{11ab^{2}}$