A computer has a two-level cache. Suppose that 65% of the memory references hit on the first level cache, 25% hit on the second level, and 10% miss. The access times are 2ns (L1), 8ns (L2), and 30ns (main memory). The times for the level 2 cache and main memory start counting at the moment it is known that they are needed (e. g. level 2 cache access does not even start until level 1 cache miss occurs). What is the average access time