The answer is 6176 EXPLANATION: The first and the last number of the series is same and it starts from 1 and incremented by 1. i.e 1a1,2b2,3c3,............etc The middle number of 1st number(121)=2 The middle number of 2nd number(232)=3(1+2)[adding 1st no and middle no of 121] The middle number of 3rd number(353)=5(2+3)[from232] The middle number of 4th number(484)=8(3+5)[from353] The middle number of 5th number(5125)=12(4+8)[from484] hence the middle number of 6th number be 17(5+12)[from 5125] so the next number in the series is 6176
6176
Increment in the first & last value by 1.
Increment in middle value in the order - 1 ,2,3,4,5 in each step. So ,
In 5125 ---> (5+1)(12+5)(5+1) = 6176.