Consider the random variable $$ representing the duration of a communication task in a computer network. The

communication task may encounter different outcomes based on the network conditions.

$=0$ represents the duration when the network line is busy or when there is no response to the communication attempt.

The network is busy or there is no response with probability $0\mathrm{.}3.$

$$ If the communication is successful, the duration of the communication task $()$ follows an exponential distribution with

a rate parameter $.$ The expected value of W given that the communication is successful is $[$ uccessful

communication$]=3$