A computer has a base CPI of 2, and a memory system with two levels of caches L1 and L2. The CPU frequency is 2Ghz. The L1 cache miss rate is 4%. 25% of accesses to the L2 cache produce a miss. L2 cache access time is 10 cycles. If the miss penalty to main memory is 50 cycles, what is the CPI with the 2 cache ? Answer 4.0