A group of college students is volunteering for Help the Homeless during their spring break. They are putting the
finishing touches on a house they built. Working alone, Irina can paint a certain room in 8 hours. Paulo can paint the
same room in 7 hours. Write an equation that can be used to find how long it will take them working together to paint the
room. How many hours will it take them to paint the room? If necessary, round your answer to the nearest hundredth.
8/x + 7/x = 1; 15 hours
1/8 + 1/7 = 1/x; 7.5 hours
x/8 + x/7 1; 3.73 hours
x/8 + x/7 = 1; 1.87 hours
The correct equation is:
1/8 + 1/7 = 1/x
Solving for x:
7/56 + 8/56 = 1/x
15/56 = 1/x
x = 56/15
x ≈ 3.73 hours
So, it will take Irina and Paulo approximately 3.73 hours to paint the room together.