(i)[3]
Find $d$ in terms of $a$.
(ii)[2]
Find the $100$th term in terms of $a$.
Mathematics 9709 · AS & A Level · Series
Series — practice question
For an arithmetic progression with first term $a$ and common difference $d$, it is stated that the sum of the first $200$ terms is $4$ times the sum of the first $100$ terms.