All of the following are examples of extracurricular activities except:

a. participating in a science lab after school.
b. being a member of the school chess club.
c. playing for the school football team.
d. participating in the school play.

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?