📢 Too many exams? Don’t know which one suits you best? Book Your Free Expert 👉 call Now!

    Question

    Average weight of a group of ‘x’ persons increased

    by 1 kg when a person weighing 70 kg joined. Later, the average increased by 1.6 kg when two persons weighing 65 kg each joined. Find the number of people in the group.
    A 28 Correct Answer Incorrect Answer
    B 48 Correct Answer Incorrect Answer
    C 42 Correct Answer Incorrect Answer
    D 36 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ,

    (xy + 70) = (x + 1)(y + 1) Or, xy + 70 = xy + y + x + 1 Or, y + x = 69 ------------(I) (xy + 130) = (x + 2)(y + 1.6) Or, xy + 130 = xy + 2y + 1.6x + 3.2 Or, y + 0.8x = 63.4 ------------(II) From (I) & (II): 69 – x = 63.4 – 0.8x Or, 0.2x = 5.6 x = 28 ∴ Value of ‘x’ = 28

    Practice Next
    More Average Questions

    Relevant for Exams:

    ask-question