What is the missing number '?' in the series 36, 28, 24, 22, ?

Given: 36, 28, 24, 22, ?

Logic: 8, 4, 2  (the difference is dividing by 2 each time)

36 - 28 = 8

28 - 24 = 4

24 - 22 = 2

Same pattern follow on next term,

22 - 1 = 21

So, the next term is 21.

Thus, the correct answer is (c).