Hamacher book. They considered miss penalty to include the cache access time. I am really confused. If you just put numbers in formula I suppose we can get 7.5. But it doesn't sound logical. Why would they consider two separate memories and then name them 'Main memory' and 'cache'?
What definition of miss penalty you are following--
1)Extra time required to load block from main memory to cache when miss occurs.
One which Arjun Sir followed in below question-
2)Time required to access data when miss occurs.(This is given in Hamacher)
Confusion is do we consider cache access time in miss penalty itself?