Question 489266
it takes you 30 minutes to rake the yard and it takes your brother 45 minutes, how long would it take for you both to rake the yard together?
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Here's pretty easy method,
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let x = time required, when raking together (in minutes)
let the completed job = 1 (a raked yard)
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Each man will do a fraction of the job, the two fractions add up to 1
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{{{x/30}}} + {{{x/45}}} = 1
multiply by by 90 to clear the denominators, results
3x + 2x = 90
5x = 90
x = 90/5
x = 18 minutes working together
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