12 boys and 16 girls can do a piece of work in 10 days while 13 boys and 24 girls can do the same work in 8 days. Find the time taken by 15

Question

12 boys and 16 girls can do a piece of work in 10 days while 13 boys and 24 girls can do the same work in 8 days. Find the time taken by 15 boys and 20 girls to do the same work

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Kylie 1 month 2021-08-16T18:13:31+00:00 1 Answer 0 views 0

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    2021-08-16T18:14:51+00:00

    Answer:

    12 and 1/2 days or 12.5 days

    Step-by-step explanation:

    let boys be a and girls be b

    12a + 16b = 10———–eq.1

    13a + 24b= 8————-eq.2

    Then,

    15a + 20b = ?

    Solving eq.1 and eq.2 we get a and b

    eq.1 *(3/2) = 18a + 24b = 15

    eq.2 =. 13a + 24b = 8

    subtract : 5a = 7

    a=(7/5) and b = -(17/40)

    So,

    15(7/5) + 20(-17/40) = ( 840-340)/40 = 500/40 = 12.5

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