SOLUTION: John and sue completed a job in 20 hours. If John worked twice as many hours as Sue, find how many hours each person worked?

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Question 399132: John and sue completed a job in 20 hours. If John worked twice as many hours as Sue, find how many hours each person worked?
Found 2 solutions by robertb, lpinkney777:
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
1%2Fj+%2B+1%2Fs+=+1%2F20
Also, j = 2s.
Then 1%2F%282s%29+%2B+1%2Fs+=+1%2F20
<==> 0.5%2Fs+%2B+1%2Fs+=+0.05 <==> 1.5%2Fs+=+0.05
==> s = 30, # hours worked by Sue, and 2s = 60, # hours worked by John.

Answer by lpinkney777(1) About Me  (Show Source):
You can put this solution on YOUR website!
Let x = # of hours that Sue worked
2x = # of hours that John worked
20= # of hours that it took to complete the job
20 + x = total # of hours worked (Assuming that they worked together x hours)
# of hours that Sue worked + number of hours that John worked = total # of hours worked
x + 2x = 20 + x
subtract x from both sides to get:
2X = 20
divide both sides by 2 to get:
X = 10
SO 2X = 20
Sue worked 10 hours and John worked 20 hours
Explanation: Sue and John worked together the first 10 hours and then John worked the last 10 hours by himself. John, therefore worked the entire 20 hours on the project and Sue only worked 10 of the 20 total hours on the project.