Avg Access time=hit*cache hit time+(1-hit)*cache miss time
so 40=h*50+(1-h)*150
or 40=150-100h
or h=110%...so ans would be none of these
Actually I have given this exam and I have seen in their solution that they consider Avg Access time as 60ns(instead of 40ns) and solved it.So it is a printing mistake.
