9514 1404 393
Answer:
2 hours 30 minutes
Explanation:
Effort is measured in people-hours per house. Here, the effort to deliver one leaflet is ...
(3 people)(2.5 hours)/(270 houses) = 1/36 people-hours/house
Then the number of hours (h) for 5 people and 450 houses is ...
(5 people)(h hours)/(450 houses) = 1/36 people-hours/house
h = (1/36)(450/5) = 2.5
It will take 2 hours 30 minutes to deliver to 450 houses.
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Alternate solution
The time is (assumed) inversely proportional to the number of people, so increasing the number of people from 3 to 5 multiplies the time by 3/5. The time is proportional to the number of houses, so increasing the number of houses from 270 to 450 multiplies the time by 450/270 = 5/3. The time for the second task is (3/5)(5/3) = 1 times the time for the first task.
2 1/2 hours is 2 hours 30 minutes.