A demand paging system take 100 time unit to service a page fault and 300 time units to replace a dirty page.Memory access time is 1 time unit .The probability of a page fault is p . In case of page fault ,the probability of page being dirty also p.It is observed that average access time is 3 times units.Then the value of p is
(a)0.194 (b)0.233
(c)0.514 (d)0.981