At what levels should lab costs be broken down?

In an array based representation of a complete binary tree, which of the following represents the parent of node tree[i]?

a) tree[i–2] b) tree[(i–1)/2] c) tree[2i–1] d) tree[2i–2]

Schemas normally use the ______ extension.

a) .shm b) .sch c) .xsd d) .schema