Consider an assembly program that contains instructions of classes: Add, Subtract, Divide, and Store with the following information:

$\backslash$table$[[$Class$,$Number of instructions,CPI$],[$Add$,5{10}^6,2],[$Subtract$,5{10}^6,2],[$Divide$,7{10}^6,4],[$Store$,7{10}^6,6]]$

The program is executed by a processor with a $4$ GHz clock rate. Answer the following questions:

A$.$ Find the total number of clock cycles executed by this processor.

B$.$ What is the average CPI of the program?

C$.$ How much we must improve the CPI of the class 'Store' instructions if we want the program to run $1\mathrm{.}5$ times faster?

D$.$ What CPI of class 'Store' instructions we should use to have the program run $15\%$ faster?

E$.$ By how much is the execution time of the program improved if the CPI of classes 'Add' and 'Subtract' instructions are reduced by $30\%$ and the CPI of class 'Divide' and 'Store' instructions is reduced by $40\%$