3 Way Matching Question

Hello,

We are on Financials 9.0.  We are having some confusion at times when trying to match muiltiple vouchers and receipts against a PO line. These are not Amount Only POs.

For a simple example like a PO with a QTY of 3 and total amount $1200.00, we are expecting 3 vouchers/invoices (each QTY of 1 and value $400), and three separate receipts as well (QTY of 1 for each received)

1) Will the PO close when the first voucher comes in and matches? Or will it wait for all three vouchers to come in?

2) If we have received all 3 items at different times, do we need to create 3 receipts or can we just do one receipt for a QTY of 3?