## Problem 1: An undergraduate business student has purchased a laptop computer f

Problem 1: An undergraduate business student has purchased a laptop computer for use during exams. This laptop is perfectly reliable except for two parts:
its microchip which has a failure rate of one in every 15 hours of operation; and its battery which has a failure rate
of one in every 20 hours of operation.

Assuming that a new battery has just been installed what is the probability that the battery will perform reliably during a 1 hour exam?

Problem 2: An undergraduate business student has purchased a laptop computer for use during exams. This laptop is perfectly reliable except for two
parts: its microchip which has a failure rate of one in every 10 hours of operation; and its battery which has a
failure rate of one in every 30 hours of operation.

Assuming that a new battery has just been installed what is the probability that the LAPTOP will FAIL during a 1
hour exam?

Problem 3:

An undergraduate business student has purchased a laptop computer for use during exams. This laptop is perfectly reliable except for two parts: its
microchip which has a failure rate of one in every 20 hours of operation; and its battery which has a failure
rate of one in every 20 hours of operation.

Assuming that a new battery has just been installed what is the probability that the LAPTOP will perform reliably during a 1 hour
exam?

Problem 4:

An undergraduate business student has purchased a laptop computer for use during exams. This laptop is perfectly reliable except for two parts:
its microchip which has a failure rate of one in every 25 hours of operation; and its battery which has a
failure rate of one in every 35 hours of operation

Assuming that a new battery has just been installed and the student brings one spare fully charged battery with him what is the probability
that the LAPTOP will perform reliably during a 2 hour exam?

Problem 5: An undergraduate business student has purchased a laptop computer for use during the upcoming semester. This laptop
is very reliable but she is concerned that the battery will wear out before the end of the semester. According to the Manufacturer on average
the battery will wear out in 130 hours with a standard deviation of 4 hours. After looking at her course schedule she
anticipates 124 hours of time will be needed working on the laptop. What is the probability that the battery will last this amount of
time or longer?