using formula find the sum of first 10 terms of the series 3+7+11+..​

2 thoughts on “using formula find the sum of first 10 terms of the series 3+7+11+..​”

1. Answer:

   210

   Step-by-step explanation:

   the series are in ap

   sum of terms in ap=

   [tex] \frac{n}{2}(2a+(n-1)d)[/tex]

   =10/2(2*3+(10-1)4)

   =5(6+36)

   =42*5

   =210

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2. Answer:

   n=10, a=3 ,d=4

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

   S(10) = 10/2[2×3 + (10-1)4]

   = 5[6+36]

   = 5×42

   = 210

   Step-by-step explanation:

   the sum of first 10 terms of the given series is 210.

   Reply