Select the number from among the given options that can replace the question mark (?) in the following series.
73, 70, 64, 55, ?

Correct option is A

Given: 73, 70, 64, 55, ?
Logic: The series is decreasing by 3, 6, 9, 12 and so on.
73 – 3 = 70
70 – 6 = 64
64 – 9 = 55
55 – 12 = 43
The correct answer is (a) 43.