A QA engineer must isolate exactly one poisoned wafer from a batch of 1000 wafers. The chemical test strip turns blue if exposed to the poison, but it takes exactly 24 hours to develop. The engineer has exactly 24 hours to determine the culprit. Assuming samples from multiple wafers can be combined onto a single test strip without diluting the effect, what is the absolute minimum number of test strips required to guarantee finding the poisoned wafer?
Because the engineer only has time for one 24-hour testing cycle, all tests must run in parallel. This is a classic binary encoding problem. Each wafer is assigned a unique 10-bit binary number (since 2^10 = 1024, which is enough to cover 1000 wafers). You use 10 test strips, representing the 10 bits. Wafer #N is added to strip #X if the Xth bit of N's binary representation is a 1. After 24 hours, the pattern of blue strips reveals the exact binary ID of the poisoned wafer.
