Seventy percent of service calls regarding kitchen appliance

Seventy percent of service calls regarding kitchen appliances involve a minor repair. For example, the customer did not read the instructions correctly or perhaps failed to connect the appliance correctly. These service calls cost $90. Service calls for major repairs are more expensive. Forty percent of service calls for major repairs cost the customer $200 or more. What is the probability that a randomly selected service call costs $200 or more?

The probability a randomly selected service call costs $200 or more is:         (Type an integer or a decimal.)

Solution

P(200 or more) = P(major) * P(200 or more given major) = (1-0.7) * 0.4 = 0.12