Question 03 Problem Solving: Diagnostic GMAT Official Guide

 
Question 5 (PS25011.02): GMAT Online Question Bank (GMAT Official Guide 2021 and beyond)

Video explanation: The sequence $a_1, a_2, a_3,…,a_n,…$ is such that $a_n=\dfrac{a_{n-1}+a_{n-2}}{2}$…