In the sequence 1, 4, 7, 10, 13, …, what is the SUM of the first 5 terms?
A25
B30
C35
D40
Answer & Solution
Correct answer: C. 35
Terms: 1 + 4 + 7 + 10 + 13 = 35. Or use sum formula for arithmetic series: S = n/2 × (2a + (n−1)d) = 5/2 × (2×1 + 4×3) = 5/2 × 14 = 35.
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