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Question 511128: Tina can wash the windows of an office building in 3/4 the time it takes her apprentice. One day they worked together for 2hrs. 16mins. and then Tina continued alone. It took her 4hrs. 32 mins. more to complete the job. How long would it take her apprentice to wash all the windows alone?
3/4(x) + x = 544
3x + 4x = 2176
7x = 2176
x = 310.86
310.86/60 = 5hr 11mins but this can't be right
Answer by solver91311(24713)   (Show Source):
You can put this solution on YOUR website!
Let  represent the number of minutes it would take the apprentice working alone to complete the part of the task that Tina and the apprentice worked on together. Then  is the number of minutes Tina would have taken on that part of the task if working alone. Then the apprentice could do  of that part of the job in one minute, and Tina could do  of that part of the job in one minute. Since 2 hours and 16 minutes is 2 times 60 plus 16 equals 136 minutes, working together they performed  of the job in one minute.
You can check the arithmetic for yourself, but it comes out to  minutes.
That is the amount of time, working alone, it would take the apprentice to do the part where they worked together.
The amount of time Tina would take for that same part of the job would simply be 3/4 of that time, or  minutes.
Tina, then, working by herself would have taken 238 minutes to do the first part and then 272 minutes (4 hrs, 32 minutes) to do the second part for a total of 510 minutes.
But if Tina takes  of the time the apprentice takes, then the apprentice takes  of the time that Tina takes. So the apprentice would take:
 minutes or 11 hours, 20 minutes.
John
My calculator said it, I believe it, that settles it
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