SOLUTION: Johnathan can type a 20 page document in 40 minutes. Susan can type it in 30 minutes, and Jack can type it in 24 Minutes. Working together, how much time will it take them to type

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Question 83482: Johnathan can type a 20 page document in 40 minutes. Susan can type it in 30 minutes, and Jack can type it in 24 Minutes. Working together, how much time will it take them to type the same document?
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Start by finding the rate at which each person types.
If Johnathan can type the entire document in 40 minutes, then he can type 1/40 of the document in 1 minute.
If Susan can type the entire document in 30 minutes, then she can type 1/30 of the document in 1 minute.
If Jack can type the entire document in 24 minutes, then he can type 1/24 of the document in 1 minute.
Working together, they can type 1/40 + 1/30 + 1/24 of the document in 1 minute.
1%2F40+%2B+1%2F30+%2B+1%2F24+=+3%2F120+%2B+4%2F120+%2B+5%2F120=12%2F120+=+1%2F10
So, together, they can type 1/10 of the document in 1 minute.
Therefore, it will take them 10 minutes to type the entire document.