Question

What is the 33rd term for this arithmetic sequence... 12,7,2,-3,-8...

Answer 1

The difference between terms if -5, so

$a_n=a_{n-1}+(-5)=a_{n-2}+2\cdot(-5)=\cdots=a_1+(n-1)\cdot(-5)$


where $a_1=12$, so

$a_{33}=12+(33-1)\cdot(-5)=-148$

making C the answer.