Consider a system with only two classes of machine language instructions A and B, with CPIA = 2 and CPIB = 5. Suppose that use of a particular compiler optimization reduces the number of executed instructions of class A for a particular program by 25%, but increases the number of executed instructions of class B by 10%. Suppose that when the compiler optimization is not used, a fraction 0.9 of the executed instructions are of class A.

(a) By what factor does the program execution time decrease with the compiler optimization?

(b) By what factor does the program execution speed as measured by MIPS decrease?