Question $3$:

Part$($a$)$ Assume that a processor has three levels of memory.

Points:

$3$

CLO $2\mathrm{.}1$

Level $1$ contains $100$ words and has an access time of $0\mathrm{.}01$ usec $((u={10}^{-6}).$

Level $2$ contains $1000$ words and has an access time of $0\mathrm{.}5$ usec $(\{$:$u=10).$

Level $3$ contains $10000$ words and has an access time of $0\mathrm{.}1$ usec $(u=10).$

Assume that $75\%$ of the accesses are found in level $1$ memory, $20\%$ in level $2$ memory, and $5\%$ in level $3$ memory. What is the average time to access a word?

Answer:

$0\mathrm{.}1125$