Q$-3.$ A processor has access to $3$ levels of cache memory. Level $1$ has an access time of $0\mathrm{.}02s$;

Level $2$ has an access time of $0\mathrm{.}2s.$ And Level $3$ has an access time $2s.$ Assume that if a word

to be accessed is in level $1,$ then the processor accesses it directly. If it is in level $2,$ then the word

is first transferred to level $1$ and then accessed by the processor. If it is in level $3,$ then it is

transferred to level $2$ and level $1$ respectively.

Suppose $80\%$ of the memory accesses are found in level $1,\%15$ of the memory accesses are found

in level $2$ and rest of are found in level $3.$ Calculate the average time to access the memory.