0The sum of the first n terms of an arithmetic progression is Sₙ = n² + 2n. What is its 10th term?A21B20C22D23 Correct answer: A ExplanationThe 10th term is S₁₀ − S₉ = (100 + 20) − (81 + 18) = 120 − 99 = 21. Join the discussion Report an error Share