Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 decade ago

Jon can type 20 pages in 40 minutes, sue can type 20 pages in 30 minutes, and Jack can type 20 pages in 24 min?

Calculate if they worked together, how long would it take all of them to type 20 pages?

5 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    Since all will be typing 20 pages, then the working formula can be simplified to

    1/20 + 1/30 + 1/24 = 1/T

    Solving for "T"

    T = 8 minutes

    This is how problems of this type are solved.

    HOWEVER, I highly doubt that the answer of T = 8 minutes is really the correct answer. First of all, how do you divide 20 pages among the three? Will Jon start from page 1 to say, page 7? Will Sue start from page 8 to say, page 14? And, will Jack type the rest of the pages?

    Anyway, I hope I understood the post correctly.

  • 1 decade ago

    Lay off Jon and Sue, and give a raise to jack. LOL.

    Jon can type 20 pages in 40 minutes.

    The pages he would type in a minute = 20/40 = 1/2 pages

    sue can type 20 pages in 30 minutes

    The pages he would type in a minute = 20/30 = 2/3 pages

    Jack can type 20 pages in 24 min

    The pages he would type in a minute = 20/24 = 5/6 pages

    Therefore the number of pages they would type together in a minute

    = 1/2 + 2/3 + 5/6

    = 3/6 + 4/6 + 5/6

    = 12/6

    = 2

    So if they type together they would type 2 pages in a minute

    Therefore it will take 20/2 minutes, i.e. 10 minutes to type 20 pages if they work together.

  • Stan
    Lv 5
    1 decade ago

    Jon types 1/2 page per minute; Sue types 2/3 page per minute, and Jack types 20/24 or 5/6 page per minute. Therefore if they work together, they will produce

    (1/2) + (2/3) + (5/6) = 2 pages per minute.

    Therefore if they have to produce 20 pages, it will take them 10 minutes.

  • 1 decade ago

    what if it took all of them to type 20 pages each?? it would take jon 40 min sue 30 min and jack 24

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  • 1 decade ago

    40min-20pg--------1min--20/40pg=1/2pg

    30min-20pg---------1min-20/30pg=2/3pg

    24min-20pg---------1min-20/24pg

    together-----in 1 min---1/2+2/3+20/24

    =12/24+16/24+20/24

    =48/24=2pg

    so 2pg per min

    for 20pages total 10 minutes.

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