a$.$ For one of his courses, Tom has to read a book $($The Pole, by E$.$ Silvermouse$).$ He can read $2$ page per minute. Tom's boss has agreed that Tom could use his idle time for studying, as long as he drops the book as soon as a call comes in$.$ How many pages can Tom read during an $8-$hour shift?

Hint: You need to calculate the $\%$ of time that Tom is not serving a customer, i$.$e$.,$ idling $($think about the meaning of utilization$).$ Then, the total idle time in an $8-$hour shift equals $(8$ hours$)*(\%$ of idle time$).$ From there, you can get how many pages on average Tom can read during an $8-$hour shift.