Question

sigma n = 55 then n =
(A) 10
(B) 15
(C) 11
(D) 12​

Answer 1

Answer:

Step-by-step explanation:

Sn =n(n+1)1/2

55=n(n+1)1/2

110=n(n+1)

110=10(10+1)

Hence n value is 10

Answer 2

Answer:

Answer is 10

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