Sixty 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 $75. Service calls for major repairs are more expensive. Eighty 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 nothing.
(Type an integer or a decimal.)

Question

Sixty  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 ​$75. Service calls for major repairs are more expensive. Eighty 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 nothing.
​(Type an integer or a​ decimal.)

kropot72 · Answer

|dw:1437342994266:dw|
You can use the above probability tree to find the required probability.

kropot72 · Answer

|dw:1437343203097:dw|
Multiply the two values of probability that are enclosed by the circle.