The sum of the first n terms of an AP is \( 3n^2 + 5n \). If the \( m^{th} \) term of the AP is 68, then what is the value of m ?
- A. 9
- B. 10
- C. 11 ✓
- D. 12
Correct Answer: C. 11
Explanation
The nth term is derived by S_n - S_{n-1} = 6n + 2. Setting 6m + 2 = 68 gives m = 11.
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