Question 1196109
<font color=black size=3>
A slightly different approach:


1/3 hr = (1/3)*60 = 60/3 = 20 min
1 & 1/3 hr = 1 hr + 1/3 hr
1 & 1/3 hr = 60 min + 20 min
1 & 1/3 hr = 80 min


Consider a lawn that is 900 sq ft. You can replace 900 with any multiple of 3.
gardener gets 2/3 of that, they get (2/3)*900 = 600 sq ft
assistant gets 1/3 of that, they get (1/3)*900 = 300 sq ft
The fractions add to 1, and 2/3 is twice that of 1/3


gardener's rate = (600 sq ft)/(80 min)
gardener's rate = 7.5 sq ft per min


Now compute the time needed when the gardener works alone
rate*time = amount done
time = (amount done)/(rate)
time = (900 sq ft)/(7.5 sq ft per min)
time = 120 min
time = <font color=red>2 hours</font>
</font>