SOLUTION: It takes an older computer 3 times as long to send out a company's email as it does a newer computer. Working together, it takes the two computers15 minutes to send out the email.

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Question 1163558: It takes an older computer 3 times as long to send out a company's email as it does a newer computer. Working together, it takes the two computers15 minutes to send out the email. How long will it take the older computer to send out the email on its own?
Do not do any rounding.
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39613) About Me  (Show Source):
You can put this solution on YOUR website!
x, time for the new computer to do the job

1%2F%283x%29%2B1%2Fx=1%2F15
1%2F%283x%29%2B3%2F%283x%29=1%2F15
4%2F%283x%29=1%2F15
3x%2F4=15
x%2F4=5
x=20-----------time for the new to do one job

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60 minutes ------------time for the old computer to do one job

Answer by greenestamps(13195) About Me  (Show Source):
You can put this solution on YOUR website!


An alternative solution method, using logical reasoning instead of formal algebra....

The newer computer works 3 times as fast as the older, so in completing the job together in 15 minutes, the newer computer does 3/4 of the job and the older computer does 1/4 of the job.

And since the older computer does 1/4 of the job in 15 minutes, it would take it 4*15 = 60 minutes to do the whole job alone.