Find the next number in the sequence.
21, 9, 21, 11, 21, 13, 21, __
Find the next number in the following sequence: 42.00, 39.50, 37.00, 34.50, ...
Find the next number in the following sequence: 40.00, 160.00, 640.00, 2560.00...
Find the next number in the following sequence: 42.00, 39.50, 37.00, 34.50...
Find the next number in the following sequence: 4.00, 2.00, 1.00, 0.50...