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[P.S.E.B.[PS.Е.В6. Find the sum of first 15 multiples of 9. |
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Answer» multiples of 9 are 9 18 27.......a=9d=9n=15 S=n/2 (2a+(n-1)d)S=15/2 (2*9+(15-1)*9)S=7.5(18+14*9)S=7.5(18+126)S=7.5*144S=1080 |
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