how many minutes are there in 1 1/6 hours?
we count like this:
\(1\frac{1}{6} *60= \frac{7}{6} *60=70\)
so she can paint 7/8 wall in 70 minutes.
how much is it per minute?
\(\frac{7}{8*70} = \frac{1}{8*10} = \frac{1}{80}\)
and that's the correct answer!