New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    A man can complete a task in 20 days, a woman can finish

    it in 30 days, and a boy can do the same task in 60 days. To complete the task in just 3 days, how many additional men are needed if the team already includes four boys and two women?
    A 2 Correct Answer Incorrect Answer
    B 8 Correct Answer Incorrect Answer
    C 6 Correct Answer Incorrect Answer
    D 4 Correct Answer Incorrect Answer
    E 12 Correct Answer Incorrect Answer

    Solution

    Let the total work be 60 units. {LCM 20, 30 and 60} So, efficiency of each man = (60/20) = 3 units/day And efficiency of each woman = (60/30) = 2 units/day And efficiency of each child = (60/60) = 1 unit/day Work to be done on each day = 60 ÷ 3 = 20 units Let number of men required to finish the work in 3 days be 'x'. So, (3 X x) + (2 X 2) + (4 X 1) = 20 Or, 3x + 4 + 4 = 20 Or, 3x = 12 So, x = 4 So, 4 men should join to finish the work in 3 days.

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