Multiple choice Find the missing term of the series: 2, 9, 39, 161, ?, 2613 651 551 441 781 951 Reveal answer Fill a bubble to check yourself A Correct answer Explanation The series is 2, 9, 39, 161, ?, 2613. Pattern: 2*4+1=9, 9*4+3=39, 39*4+5=161, 161*4+7=651, 651*4+9=2613. The missing term is 651.