A$.$ Write a c$++$ program that will do the following:

$$ Ask the user for their hypothetical final accumulated grade in this course as an integer variable.

$$ Use nested if$...$else statements to match their accumulated grade with correct letter grade. The

pseudocode will look like:

Prompt user to enter their final accumulated grade,

If student$$s grade is greater than or equal to $90,$

Print $$A$.$

Else

If student$$s grade is greater than or equal to $80,$

Print $$B$$

Else

If student$$s grade is greater than or equal to $70,$

Print $$C$$

Else

If student$$s grade is greater than or equal to $60,$

Print $$D$$

Else

Print $$F$$

$$ You should try $5$ different total grades to test each if statement.

$$ Now use while statement with counter$-$controlled structure to perform the following addition to your

program:

Define total, grade counter and grades as integer, and average as double

Set total grades to zero

Set grade counter to one or zero

While grade counter is less than or equal to $7,$

Prompt the user to enter the next grade,

Input the next grade and echo the grade and its equivalent Letter grade separated by

tab escape sequence $(\backslash$t$)$ back to user, the output should look like

$[$Enter grade: $88$

Your grade is: $88$ and your letter grade is: B$]$

Add the grade into the total

Add one to the grade counter

Set the class average to the total divided by $7,[$by using the unary cast operator to obtain

fractional results from the division of two integers, or use very simple approach of

manipulation of integers with floats$/$doubles;

average$=$ static$\_$cast$($total$)/$grade counter

Print the total of the grades for all $7$ students

Print the class average with two decimal places

The sample output may look like:

Enter your grade: $99$

Your grade is: $99$ and your letter grade is: A

Enter your grade: $100$

Your grade is: $99$ and your letter grade is: A

Enter your grade: $88$

Your grade is: $88$ and your letter grade is: B

Enter your grade: $77$

Your grade is: $77$ and your letter grade is: C

Enter your grade: $66$

Your grade is: $66$ and your letter grade is: D

Enter your grade: $55$

Your grade is: $55$ and your letter grade is: F

Enter your grade: $89$

Your grade is: $89$ and your letter grade is: B

Class Average is $82\mathrm{.}00$

Class Total is $574$

B$.$ Write a program that reads a nonnegative integer and computes and prints its factorial. The factorial of a

nonnegative integer n is written n$!($pronounced $$n factorial$)$ and is defined as follows:

n$!=$ n$($n$1)($n$2)...1($for values of n greater than $1)$

and

n$!=1($for n$=0$ or n$=1).$