Pattern: 1620÷2-10=800≠1600. Alternative: 1620-20=1600, 1600÷2-20=780, 780÷2-150=240, 240÷2-120=0≠40. Best pattern found: 1620-20=1600, (1600-40)/2=780, (780-300)/2=240, (240-120)/2=60≠40, (60-32)/2=14≠-12. Answer 240 is the best fit among options for the missing term.