I have an array $A$ of length $n$, containing triplets (think of it as a $3times n$ matrix). Can I re-order the array (without reordering a triplet’s inner values) in time $O(nlog n)$ so that it is possible to answer the following query in $O(log n)$? Given $i$, determine the number of $j$ such that $A_{2,j} le A_{3,i}$ and $A_{1,j} le A_{2,i}$.