Find the missing term: 6, 12, 21, ?, 48

Find the missing term: 2, 9, 28, ?, 126, 126, 217, 344

Find the missing term: 28, 33, 31, 36, ?, 39

Find the missing term: 9, 27, 31, 155, 161, 1127, ?

2, 1, <sup>1</sup>/<sub>2</sub>, <sup>1</sup>/<sub>4</sub>, . . . . . . …

Find the missing term: 120, 99, 80, 63, 48, ?

Find out the wrong term: 15, 16, 22, 29, 45, 70

6, 20, 8, 14, 10, 8, 12, ... choose which pair of numbers comes next?

Find the missing term: 5, 2, 7, 9, 16, 25, ?