Find the invalid no.from the following series 12, 19, 24, 31, 36, 39	Choose the correct choice
A) 13  B) 18  C) 40  D) 39  E) 25
The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 39 is wrong.   Answer : 39
<result>D</result>
Find the invalid no.from the following series 12, 19, 24, 31, 36, 39