Q2: How many terms of following AP; 5 points 2,4,6,8,10,12==-given sum 90. * ​

Question

Q2: How many terms of following AP; 5 points
2,4,6,8,10,12——-given sum 90. *

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Nevaeh 1 month 2021-08-21T12:50:27+00:00 1 Answer 2 views 0

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    2021-08-21T12:52:18+00:00

    Answer:a=2, d=4-2=2

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

    90=n/2(2+(n-1)2)

    90×2=n(2+2n-2)

    180=n(2n)

    180=2n²

    180/2=n²

    90=n²

    n=✓90

    n=30

    So it will be 30th term

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