Question Detail
Question
The first term of an AP is 5, the last term is 45, and the sum of all terms is 400. Find the number of terms.
Correct Answer
Option A is the correct answer.
Detailed Explanation
Using S_n = (n/2)(a + l), we have 400 = (n/2)(5 + 45) = 25n, which gives n = 16.
Hint
No hint available