Question Detail
Question
If the 7th term of an arithmetic progression is 40, what is the sum of its first 13 terms?
Correct Answer
Option A is the correct answer.
Detailed Explanation
The sum is S_13 = (13/2)[2a + 12d] = 13(a + 6d). Since T_7 = a + 6d = 40, S_13 = 13 * 40 = 520.
Hint
No hint available