SOLUTION: A mason can construct a retaining wall in 15 hours. With the mason's apprentice assisting, the task takes 10 hours. How long would it take the apprentice, working alone, to const

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A mason can construct a retaining wall in 15 hours. With the mason's apprentice assisting, the task takes 10 hours. How long would it take the apprentice, working alone, to const      Log On


   

Question 403216: A mason can construct a retaining wall in 15 hours. With the mason's apprentice assisting, the task takes 10 hours. How long would it take the apprentice, working alone, to construct the wall?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their rates to find the rate working together.
In words:
(1 wall / mason's time) + (apprentice's rate) = (1 wall/time working together)
Let r%5Ba%5D = apprentice's rate of working
1%2F15+%2B+r%5Ba%5D+=+1%2F10
r%5Ba%5D+=+1%2F10+-+1%2F15
r%5Ba%5D+=+3%2F30+-+2%2F30
r%5Ba%5D+=+1%2F30
The apprentice can construct 1 wall in 30 hours