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 to the nearest hundredth if necessary.

Answer 1

To find out how long it will take them to finish the floor working together, we need to combine their individual rates of work.

Joan's rate of work is 1/12 of the floor per hour.
Jett's rate of work is 1/9 of the floor per hour.

Their combined rate of work is 1/12 + 1/9 = 3/36 + 4/36 = 7/36 of the floor per hour.

Therefore, working together, they can complete 7/36 of the floor per hour.

To find out how long it will take them to finish the entire floor, we take the reciprocal of their combined rate:

1 / (7/36) = 36/7 ≈ 5.14 hours

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