A small model-airplane motor has 4 starting components: key, battery, wire, and glow plug. What is the probability that the system will work if the probability that each component will work is as follows: key (0.998), battery (0.95), wire (0.999), and plug (0.995)? Solution Probability of choosing the starting component as key or battery or wire or plug = 1/4 Hence the probability that the model starts =(1/4*0.998)+(1/4*0.95)+(1/4*0.999)+(1/4*0.995)=0.9855.

1. A small model-airplane motor has 4 starting components: key, battery, wire, and glow plug.
What is the probability that the system will work if the probability that each component will
work is as follows: key (0.998), battery (0.95), wire (0.999), and plug (0.995)?
Solution
Probability of choosing the starting component as key or battery or wire or plug = 1/4
Hence the probability that the model starts
=(1/4*0.998)+(1/4*0.95)+(1/4*0.999)+(1/4*0.995)=0.9855