question   about  Littles Law  
i know that littles law state

    avarage number of things in system is product  of the avarage rate at which things  leave the system  and avarage time each one  one spends  in the system
or  

     n=x*(r+z);
    x-throughput
      r-response time
     z-think time
      r+z - avarage  response time
now i have question about problem from programming pearls

  Suppose that system makes  100 disk accesses  to process transaction(although  some system require fewer some system  several hundred disk access per transaction) how many transaction per hour per disk can the system handle?

please help
question   about  Littles Law  
===

i know that littles law state

    avarage number of things in system is product  of the avarage rate at which things  leave the system  and avarage time each one  one spends  in the system
or  

     n=x*(r+z);
    x-throughput
      r-response time
     z-think time
      r+z - avarage  response time
now i have question about problem from programming pearls

  Suppose that system makes  100 disk accesses  to process transaction(although  some system require fewer some system  several hundred disk access per transaction) how many transaction per hour per disk can the system handle?

please help