SOLUTION: Please help me solve the following problem: Mark and Rachel both work for Smith Landscaping Company. Mark can finish a planting job in 4 hours, while it takes Rachel 5 hours to

Algebra ->  Coordinate Systems and Linear Equations  -> Linear Equations and Systems Word Problems -> SOLUTION: Please help me solve the following problem: Mark and Rachel both work for Smith Landscaping Company. Mark can finish a planting job in 4 hours, while it takes Rachel 5 hours to      Log On


   

Question 111120This question is from textbook
: Please help me solve the following problem:
Mark and Rachel both work for Smith Landscaping Company. Mark can finish a planting job in 4 hours, while it takes Rachel 5 hours to finish the same job. If Mark and Rachel will work together on the job, and the cost of labor is $40 per hour, what should the labor estimate be?
Thank you This question is from textbook

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Mark and Rachel both work for Smith Landscaping Company. Mark can finish a planting job in 4 hours, while it takes Rachel 5 hours to finish the same job. If Mark and Rachel will work together on the job, and the cost of labor is $40 per hour, what should the labor estimate be?
:
Let t = time required when working together:
:
Let the completed job = 1
:
t%2F4 + t%2F5 = 1
:
Multiply equation by 20 to get rid of the denominators
20*t%2F4 + 20*t%2F5 = 20(1)
:
Cancel out the denominators and you have:
5t + 4t = 20
:
9t = 20
:
t = 20%2F9 hrs
:
Find the labor cost:
20%2F9 * 40 = $88.89, probably estimate $90 or $100