Question

    In each of the following questions a number is wrong in the series. Find out the wrong number.

    217     210       236       299      423     640

    A 640 Correct Answer Incorrect Answer
    B 236 Correct Answer Incorrect Answer
    C 423 Correct Answer Incorrect Answer
    D 210 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    217 + (23 - 1) = 210 210 + (33 - 1) = 236 236 + (43 - 1) = 299 299 + (53 - 1) = 423 423 + (63 - 1) =  638

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