8- Suppose you have a memory system that has 3 main pillars, the cache to store data so that future requests for that data can be served faster, main memory which is the fundamental storage unit in a computer system and a virtual memory that provides an abstraction of the storage resources that are actually available on a given machine. Now assume that the access time of the cache is 10 nanoseconds and the cache hit rate is 70%. As for the main memory, it has an access time of 150 nanoseconds and a hit rate of 80%. Lastly, access time of the virtual memory is 20 milliseconds and a hit rate of 100%. Calculate the average access time for requests that reach the cache? (10 points)