Average access time= Avg. access time for TLB HIT + avg. access time for TLB MISS.
Avg. access time for TLB HIT= TLB hit ratio*(M.M access time)
Avg access time for TLB MISS= TLB miss ratio*(M.M access time + Avg time for page fault + Avg. time for Dirty page replacement)
Avg access time = (1-Pt)(Tm) + Pt*(Tm + Pp(Td+Pd*Td))
Avg access time = (1-0.1)(1) + 0.1*(1 + 0.0002(104+0.5*104))=1.3 units