1. System A consists of a single ring with 100 stations, one per repeater. System B consists of four 25 stations rings linked by a bridge. If the probability of a link failure is P_l, a repeater failure is P_r , and a bridge failure is P_b , derive an expression for parts (a) to (e). 50 points

Known:

• System A: Single ring with 100 stations
• System B: Four 25-station rings linked by a bridge.
• Probability of link failure: