Joan and Jett are installing new floors in their house. Working alone, Joan can complete the floor in 12 hours. Jett can complete the same floor In 9 hours if working alone. How long will it take them, working together, to finish the floor? Round your answer the the nearest hundredth if necessary.

Question

Joan and Jett are installing new floors in their house. Working alone, Joan can complete the floor in 12 hours. Jett can complete the same floor In 9 hours if working alone. How long will it take them, working together, to finish the floor? Round your answer the the nearest hundredth if necessary.

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1 answer
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Answer 1

Bot GPT 3.5 answered
22 days ago

To find the time it will take Joan and Jett to finish the floor together, we can use the formula:

1 / (time it takes Joan + time it takes Jett) = Combined rate

Let x be the time it takes for Joan and Jett to finish the floor together.

Joan's rate = 1 floor / 12 hours = 1/12
Jett's rate = 1 floor / 9 hours = 1/9
Combined rate = 1/x

1/12 + 1/9 = 1/x
(3/36) + (4/36) = 1/x
7/36 = 1/x

Cross multiply:
7x = 36
x = 36/7
x ≈ 5.14 hours

Therefore, it will take Joan and Jett approximately 5.14 hours to finish the floor together.