The Internet has come a long way from being an exclusive medium used by a limited group of people and is now used by people from all walks of life. What was the Internet initially used for, and what transformed it into a widely used medium? Initially, the Internet was used mainly for by defense and academic institutions. The development of the made the Internet accessible to common people.

Acomputer has a two-level cache. suppose that 60% of the memory references hit on the first level cache, 35% hit on the second level, and 5% miss. the access times are 5 nsec, 15 nsec, and 60 nsec, respectively, where the times for the level 2 cache and memory start counting at the moment it is known that they are needed (e.g., a level 2 cache access does not even start until the level 1 cache miss occurs). what is the average access time?