MPOTD

Let $a_1,a_2,a_3,\dots$ be an Arithmetic Progression (AP) such that $a_1=5$ and $a_{10}=23$. If $S_n$ is the sum of the first $n$ terms of the series S=1/a1​a2​1​+1/a2​a3​1​+1/a3​a4​1+…, then the value of $S_{10}$ is:

idk what does that mean