Os+ disk+ntpel question

Question

Disk cache have cache access not in heiracrchially manner by default?? I am getting 76 as answer

Answer 1

The effective time in this case will be calculated as :

(1-p)*cache access time + p*(cache access time+disk access time)

=  0.25 + 0.75 * 101

=  76 

Hence the answer should be 76 ms since on miss also cache access time needs to be included as cache is accessed first then we come to know whether there is hit or miss.