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


    Question

    The average of a set of 's' numbers is 50. If 120 is

    added to the set, then the average of the set becomes 50.4. Find the value of '4 X (s - 20)'.
    A 616 Correct Answer Incorrect Answer
    B 600 Correct Answer Incorrect Answer
    C 650 Correct Answer Incorrect Answer
    D 640 Correct Answer Incorrect Answer
    E 630 Correct Answer Incorrect Answer

    Solution

    Sum of all 's' numbers = 50s
    ATQ:
    (50s + 120) / (s + 1) = 50.4
    Multiplying both sides by (s + 1):
    50s + 120 = 50.4(s + 1)
    50s + 120 = 50.4s + 50.4
    120 - 50.4 = 50.4s - 50s
    69.6 = 0.4s
    s = 174
    4 X (s - 20):
    4 X (174 - 20) = 4 X 154 = 616

    Practice Next

    Relevant for Exams:

    ask-question