Suppose you have two different methods to accelerate a program. They have the same cost but cannot be used at the same time. Method 1 can accelerate 40% of the program by 10 times. Method 2 can accelerate 20% of the program by 20 times and 30% of the program by 6 times. a) (4 points) Comparing the speedup of both methods, which would you like to choose? b) (1 points) If you keep optimizing the same 40% of the program, what is the best speedup you can achieve?