In an AP, the notation $S_r$ denotes the sum of first $r$ terms, $S_p=q$ and $S_q=p$. Then $S_{p+q}$

Question

In an AP, the notation $S_r$ denotes the sum of first $r$ terms, $S_p=q$ and $S_q=p$. Then $S_{p+q}$ is equal to

Professor PC Thomas Classes · Answer

Standard AP property: $S_{p+q} = -(p+q)$.