You are trying to rely on internal controls and are going to test the prenumbered purchase orders to ensure there are none missing and no duplicates. What type of test would be the most effective in this instance?

An auditor has documented their understanding of the internal control of the sales cycle of a client but is not going to test the operational effectiveness of those controls. In this instance, which test would be the most effective in determining the existence of A/R as of the balance sheet date?

Which type of audit test is the only test that is required to be utilized during an audit?