Answer:
0.625
Step-by-step explanation:
We are told that the agent has 8 keycards.
We are also told that only one of the keycards can open each home.
Now, if the agent took 3 out of the 8 keycards with him, it means that;
Probability of opening by the keycards = ⅜
We are told that 40% or 0.4 of these homes were left unlocked.
This means that 60% or 0.6 are those that will require a key card.
Thus, probability of agent getting into a specific home is;
P(agent getting into a specific home) = 0.4 + 0.6(⅜)
P(agent getting into a specific home) = 0.4 + 0.6(0.375) = 0.625