the sum of all two digit order number is​

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the sum of all two digit order number is​

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Adeline 2 months 2021-08-11T14:43:39+00:00 2 Answers 0 views 0

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    0
    2021-08-11T14:45:07+00:00

    Step-by-step explanation:

    Sum of ‘n’ numbers is

    Sn = n/2 (2a+(n-1)d)

    first 2 digit number = 10, difference between any 2 successive numbers = 1, last number= 99, no.of digits from 10 to 99 = 90

    Sn = 90/2 [2(10)+(90-1)1]

    Sn = 45[20+89]

    Sn = 45[109]

    Sn = 4905

    therefore, sum of all 2 digit numbers = 4905

    2nd method:

    Sn = n/2 [a+l]

    first 2 digit number (a) = 10, last number(l) = 99, no.of digits from 10 to 99 = 90

    Sn = 90/2 [10+99]

    Sn = 45(109)

    Sn = 4905

    0
    2021-08-11T14:45:08+00:00

    Answer:

    ok

    Step-by-step explanation:

    dont know dkfjsksknzkjkdJJrxfsa0

    thnx for free points

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