Question

Find S3 for the A.P. 3, 5, 7, 9, -----------​

Answer 1

Step-by-step explanation:. 3+ 5+ 7 = 15 so

15 is the answer for above question

Answer 2

Answer:

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

S3 = 3/2 x 2x3+ (3-1)2

S3 = 3/2 x 6 + 4

S3 = 3/2 x 10

S3 = 3x 5

S3 = 15

Step-by-step explanation:

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