WBCS Preliminary Examination 2021 — General Studies · Question 185 of 200

Answer: (B) 226

The differences between successive terms are perfect cubes: $2-1=1^3$, $10-2=8=2^3$, $37-10=27=3^3$, $101-37=64=4^3$. The next difference is $5^3=125$, so the missing term is $101+125=226$. In other words each term is 1 plus a running sum of cubes: $1+1^3=2$, $1+1^3+2^3=10$, $1+1^3+2^3+3^3=37$, and so on. Tip: when the differences grow quickly, test squares and cubes first.