Mathematics 9709 · AS & A Level · Series

Series — practice question

An arithmetic progression has first term $1.5$, and the total of its first ten terms is $127.5$.

(a)[2]

Find the common difference for this progression.

(b)[5]

Find the sum of every term in the arithmetic progression whose values lie between $25$ and $100$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “ $5(3+9d)=127.5$” …