Wade and Shane work together at local aquarium.

Question

Wade and Shane work together at the local aquarium. It takes Wade 30 minutes to clean the jellyfish tanks. Since Shane is new to the job, it takes him longer to perform the same task. When working together, they can perform the task in 21 minutes. How long does it take Shane to do the task by himself?

Answer 1

Hi Matt, to solve work problems, create an equation representing the amount of work each individual can do in one unit of time.

 

Wade: can do 1/30 units of work in one unit of time.

 

Shane: can do 1/x units of work in one unit of time.

 

Together: Then can to 1/21 units of work in one unit of time.

 

Equation:

 

1/30 + 1/x = 1/21

 

Solve for x:

 

Clear fractions by multiplying the entire equation by 630x, the common denominator.

 

630x * (1/30 + 1/x = 1/21)

 

21x + 630 = 30x

 

Combine terms:

 

9x = 630

 

x = 70

 

It will take Shane 70 minutes to do the work alone.

 

Questions?