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

    Question

    The average of n numbers is 84. If each of 75% of the

    numbers is increased by 6 and each of the remaining numbers is decreased by 9, then the new average of the numbers is:
    A 81.75 Correct Answer Incorrect Answer
    B 84 Correct Answer Incorrect Answer
    C 86.25 Correct Answer Incorrect Answer
    D 88 Correct Answer Incorrect Answer

    Solution

    Let the total number = 100 Average = 84 (given) Total = 84 × 100 = 8400 75% of 100 = 75 Total increase in 75 numbers = 75 × 6 = 450 Total decrease in 25 numbers = 25 × -9 = 225 ∴ Total increase in 100 numbers = 450 – 225 = 225 Now Total = 8400 + 225 = 8625 Average = 8625/100 = 86.25%

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