Multiple choice Find the missing term in the following number series. 200 209 237 302 ? 425 399 485 428 416 Reveal answer Fill a bubble to check yourself D Correct answer Explanation The differences are: 209 - 200 = 9 = 3², 237 - 209 = 28 = 3³ + 1, 302 - 237 = 65 = 4³ + 1. The next difference should be 5³ + 1 = 126. So 302 + 126 = 428.