Consider three different processors P1, P2, and P3 executing the same instruction set. P1 has a 4GHz clock rate and a CPI of 2. P2 has a 2.5GHz clock rate and a CPI of 1.0, P3 has a 3GHz and a CPI of 1.2. a) Which processor has the highest performance expressed in instructions per second? b) If the processors each execute a program in 10 seconds, find the number of cycles and the number of instructions. c) We are trying to reduce the execution time by 20% but this leads to an increase of 15% in the CPI. What clock rate should we have to get this time reduction?