How much time would it take for Amy to mow 600 square feet?

Amy can mow 600 square yards of grass in $1 \dfrac{1}{2}$ hours. At this rate, how many minutes would it take her to mow 600 square feet?

MetroEye: Rate of Work

1 square yard = 1 square feet
$1 \dfrac{1}{2}$ hours = $\dfrac{3}{2}\cdot 60$ = 90 minutes

$\dfrac{600 sq yards}{1 \cdot 1 1/2 hours}$ = $\dfrac{600 sq feet}{1 \cdot H_2}$ 

Converting to same units,

$\dfrac{600\cdot 9}{90}$ = $\dfrac{600}{H_2}$ 

$H_2$ = $\dfrac{600\cdot 90}{600\cdot 9}$ = 10 minutes

Amy would take 10 minutes to mow 600 sq.feet.