.
Solve for x
Working together Ben and Frank wash 1,000 dishes in 3 hours. Ben works twice as fast as Frank.
How long does it take Frank to wash dishes alone?
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I just solved it (in semi-joking form) at this link
https://www.algebra.com/algebra/homework/Rate-of-work-word-problems/Rate-of-work-word-problems.faq.question.1112619.html
https://www.algebra.com/algebra/homework/Rate-of-work-word-problems/Rate-of-work-word-problems.faq.question.1112619.html
But if you want to get the solution in the serious algebraic form, here it is.
Let x be the Frank's rate, measured in dishes per hour.
Then the Ben rate is 2x dishes per hour.
The combined rate of work is x + 2x = 3x dishes per hour.
We are given 3x * 3 hours = 1000 dishes, or
9x = 1000 dishes
Now divide both sides of this equation by x. You will get
9 = .
It means that Frank will make all the job in 9 hours, working alone.