Answer:
3/8 backyard in 1/4 hour
Step-by-step explanation:
Her rate is (1 backyard) / (2/3 hour), or 3/2 backyard per hour.
At this rate, after 1/4 hour, she will have mowed:
3/2 backyard 1 hr
------------------------- * --------- = 3/8 backyard in 1/4 hour
1 hour 4
