Question 1190088
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1 hr = 60 min
2 hr = 120 min
2 hr, 30 min = 120 min + 30 min = 150 min


Let's say the lawn has a total area of 300 sq ft
Each boy will handle 300/2 = 150 sq ft


Each individual has a unit rate of
rate = (amount done)/(time)
rate = (150 sq ft)/(150 min)
rate = 1 sq ft per min


Assume that the 3 other boys will have the same unit rate
If so, then the combined rate of all five boys is 5 sq ft per min. This assumes that no person hinders another.


rate = (amount done)/(time)
rate*time = amount done
time = (amount done)/(unit rate)
time = (300 ft^2)/(5 sq ft per min)
time = 60 min
time = 1 hour


Answer: A) 1 hour
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