Answer :
Given that,
A group of workers can plant 2/5 acres in 7/8 days.
To find,
The unit rate in acres/day.
Solution,
To find unit rate, divide acres and days as follows:
[tex]R=\dfrac{\dfrac{2}{5}}{\dfrac{7}{8}}\ \text{acres/days}\\\\=\dfrac{2}{5}\times \dfrac{8}{7}\\\\=0.45\ \text{acres/days}[/tex]
So, the unit rate is 0.45 acres/days.