Question

Tiana can clear a football field of debris in 3 hours. Jacob can clear the same field in 2 hours. If they decide to clear the field together, how long will it take them?
50 minutes
1 hour 5 minutes
1 hour 12 minutes
5 hours

Answer 1

@Somy

Answer 2

@JungHyunRan

Answer 3

@cwrw238

Answer 4

if x is the required time then

1 /3 + 1/2 = 1/x

solve for x

Answer 5

What cwrw238 is telling you is that this type of problem is based on hours it takes a person to get a job done, specifically how much of a job can be done in 1 hour. If it takes Tiana 3 hours to get a job done, she gets 1/3 of it done in an hour. If it takes Jacob two hours to get a job done he can get 1/2 of it done in an hour. Combining their times to work together is why you add them; setting them equal to 1/x is what you do to solve for the total number of hours. You have to find the lowest common multiple among the 2, 3, and x. Any ideas here?

Answer 6

6

Answer 7

@IMStuck - good explanation

Answer 8

The LCM would actually be 6x, because you have an x down there too on the right side of the equals sign. Try that. What do you get? If you need help we can help you.

Answer 9

Thank you for the compliment, cwrw238.