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

    Question

    What is the unit digit of the sum of first 111 whole

    numbers?
    A 4 Correct Answer Incorrect Answer
    B 6 Correct Answer Incorrect Answer
    C 5 Correct Answer Incorrect Answer

    Solution

    Sum of first 11 whole numbers is 0+1+2...110 i.e n(n+1)/2 =110*111/2 =55*111 Therefore unit digit is 5

    Practice Next