This question appeared in a competitive exam. The question is:
Q. Find the unknown term in $87,89,95,107,?,157$
1)127 $\ \ \ \ \ \ \ \ $ 2)122
3)139 $\ \ \ \ \ \ \ \ $ 4)140
I tried very much to solve it but can't find the correct answer. Any hints will be appreciated.
Thanks in advance.
My effort that I did before asking this question:
I calculated the difference b/w consecutive terms. The diff is $2,6,12,20$. I was not able to recognize any pattern. After this I subtracted each term, which is less than 100, from 100 and, subtracted 100 from each term which is greater than 100. The resultant sequence is is $13,17,11,5,7,x,y$. Again I could not recognize any pattern.
It was asked in SBI Clerical Exam 27-05-2012. It is the 110th question of that exam.