35. Find the number of terms in an A.P. 18,15,12,……., – 48 and also find the sum of all
of its term

1 thought on “35. Find the number of terms in an A.P. 18,15,12,……., – 48 and also find the sum of all <br /> of its term”

1. Answer:

   no. of terms = 34

   sum of terms = -1071

   Step-by-step explanation:

   a) -48 = 18 + (n-1) -3

   -48 -18 = (n-1) -3

   -66/-3 = n-1

   n = 34

   b) Sn = 34/2 [ 2×18 + (34-1)-3]

   = 17 [ 36 + -99]

   = 17(-63)

   = -1701

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