C++ :: Calculate Simple Interest Of Given Loan Amount And Duration In Years

Your objective is to write a program that calculates the simple interest for a given loan amount and duration (in years).

Formula:

Simple interest = loan amount X interest rate X number of years
Assume interest rate is a constant 6% per year.

Specifically, your program will:
1. Output descriptive header
2. Prompt and read any customer’s first name, middle initial, and last name individually
3. Prompt and read the principal/loan amount
4. Prompt and read the duration of the loan in years
5. Calculate the interest
6. Output:
a. Customer full name
b. Principal/loan amount
c. Duration of loan
d. Interest rate
e. Interest on loan
f. Principal and interest due at end of term

OK SO THIS IS MY PROGRAM SO FAR. As you can see i got it all but i am so confused with as to for loan amount and duration of year, if i should use float or double to declare it?

i need to finish this assignment by calculating the simple interest and i dont know how or where to begin.

int main(){
system("color f0");
string firstName;
string middleInitial;
string lastName;
cout<<"Please enter your First Name: ";

[Code]...