Question

    The average of a series of 30 numbers is 70. The

    difference between the largest number and the smallest number is 140. If the largest and the smallest number are excluded from the series, the average becomes 68. What is the largest number of the original series?
    A 168 Correct Answer Incorrect Answer
    B 155 Correct Answer Incorrect Answer
    C 110 Correct Answer Incorrect Answer
    D 172 Correct Answer Incorrect Answer

    Solution

    Sum of smallest and largest number = 30 × 70 – 28 × 68 = 196 Difference of smallest and largest number = 140 ∴ Largest number = (196 +140)/2 = 168

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