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Three people take 2 1⁄2( two and a half ) hours to deliver leaflets to 270 houses

Assuming all people deliver leaflets at the same rate, how long will it take five people to deliver leaflets to 450 houses?
Give your answer in hours and minutes

User Vchar
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1 Answer

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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.

User Nadiya
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