Question: A silicon wafer has a total of 400 integrated circuits (ICs) at the beginning of its fabrication sequence. A total of 20 operations are used to complete the ICs, 5% of which arc damaged at each operation. The damages compound, meaning that an IC that is already damaged has the same probability of being damaged by a subsequent process as a previously undamaged IC. How many defect-free ICs remain at the end of the fabrication sequence?