Review question

If an AP has $S_{10}=3S_5$, what's the ratio of $u_{10}$ to $u_5$? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R8907

Suggestion

An arithmetic progression is such that the sum of the first $10$ terms is $3$ times the sum of the first $5$ terms. Find the ratio of the $10$th term to the $5$th term.

If $S_n$ is the sum of the first n terms, do we have a formula for $S_n$?

If $u_n$ is the nth term, do we have a formula for $u_n$?

Given further that the 5th term is $0.14$, calculate the sum of the first 200 terms.

Can we find the common difference with this added information?