Question

The following series series numbers proceed from any one rule, one number is missing in the series. Missed numbers are indicated by spaces. What should be the number that falls in the blank space of the series? 17, 21, 23, 27, 29, 33, 39 ,? (a) 41 (b) 42 (c) 43 (d) 44​

Answer 1

Answer: 43

Step-by-step explanation: The difference appears to be -

4, 2, 4, 2, 4, 6, __

The even differences seem arbitrary, but the odd 4 repeats. Hence the next difference will be 4 and 39+4=43.