Question Detail
Question
An arithmetic sequence has a first term 5 and 15th term 47. What is the sum of the first 15 terms?
Correct Answer
Option A is the correct answer.
Detailed Explanation
S₁₅ = n/2(a + l) = 15/2(5 + 47) = 7.5 × 52 = 390.
Hint
The notes indicate answer A.