Answer
$120$ rows
Work Step by Step
We know that Akuba knits 5 cm of scarf in 6 rows. We figure out how many rows would equal 100 cm with a proportion:
$\displaystyle \frac{5~cm}{6~rows}=\frac{100~cm}{x~rows}$
We cross-multiply:
$5*x=100*6$
$5x=600$
$x=600/5$
$x=120$ rows
