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Math

Question

A and B can do a piece of work in 72 days B and C in 120 days and A and C in 90 days in what time can A alone do it ​

2 Answer

  • B and C takes 120 days

    A and C takes 90 days

    No.of days taken by B,C and A,C all together =120+90

    =210 days

    A and B does the work in 72 days

    number of days taken C by working two times =210- 72

    =138

    number of days taken by C =138÷2

    =69

    number of days taken by A and C together =90

    number of days taken by A=90-69

    =21

  • Step-by-step explanation:

    (A+B)'s 1day work =1/72

    (B+C)'s 1 day work =1/120

    (C+A)'s 1 day work =1/90

    adding all three , 2(A+B+C)'s 1 day work =1/72+1/120+1/90

    =5+3+4/360

    =12/360

    =1/30

    (A+B+C)'s 1 day work =1/60

    Now ,A's one day work =(A+B+C)'s 1 day work - (B+C)'s 1 day work

    =1/60-1/120=2-1/120

    =1/120

    Hence , A can complete the work in 120 days.

    If it helps you then plz mark as brainliest ☺️☺️..........

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