MathDB
Arithmetic Sequence

Source: 1995 National High School Mathematics League, Exam One, Problem 1

March 2, 2020
arithmetic sequence

Problem Statement

In arithmetic sequence (an)(a_n), 3a8=5a13,a1>03a_8=5a_{13},a_1>0. Define Sn=∑i=1naiS_n=\sum_{i=1}^n a_i, then the largest number in (Sn)(S_n) is (A)S10(B)S11(C)S20(D)S21\text{(A)}S_{10}\qquad\text{(B)}S_{11}\qquad\text{(C)}S_{20}\qquad\text{(D)}S_{21}
Back to ProblemsView on AoPS