need help with memory segment problem

4. (10 points) Suppose an instruction takes an average of 0.12 microsecond to execute, and a page fault takes 195 microseconds of processor time to handle plus 15 milliseconds of disk timeo read in the page. How many pages a second can the disk transfer? Suppose one- fourth(/4)ot c pages are dirty (have been modified). It takes two page transfers to replace a dirty page. C the average number of instructions between page faults that would cause the system t the disk with page traffic, that is, for the disk to be busy all the time doing page tr o saturate ansfers (U =