Problems with returning values, using dereferencing...error C2556 error C2371

I had to write a program for class that requires sending variables by dereferencing, and returning a value through two functions.
I apologize for the lack of documentation.
Please help me!

All headers included in ptrphead.h.

#include "ptrphead.h"

void ValueF();
double GenerateF(double &NumberV);
double DivideF(double &NumberV, double Divisor);

void Halt();
void ClearS();

void ValueF()
{
     double NumberV;
     double *NumPtr = &NumberV;
     double Manipulated;

     ClearS();

     cout << "Please enter a number\n\t>";
     cin >> *NumPtr;

     cout << "\n\n";
     cout << "Original:\t" << NumberV << "\n";

//     GenerateF(NumberV);

     Manipulated = GenerateF(NumberV);

     cout << Manipulated;

     return;

}

double GenerateF(double &NumberV)
{
     double Divisor;
     double *DivPtr = &Divisor;
     double Manipulated;

     srand(static_cast<unsigned>(time(NULL)));

     *DivPtr = (rand() % 10) + 1;

//     DivideF(NumberV, Divisor);
     
     Manipulated = DivideF(NumberV, Divisor);

     return(Manipulated);
}

void DivideF(double &NumberV, double Divisor)
{
     apvector<double>Quotients(4);
     double Manipulated;
     int Counter=0;

     do{
          if(Counter<4)
          {
               Quotients[Counter] = NumberV / Divisor;
               NumberV = NumberV / Divisor;
          }
          else
          {
               Manipulated = NumberV / Divisor;
          }

          Counter++;
     }
     while (Counter<5);

     cout << setw(10) << "Cycle"
          << setw(10) << "Quotient\n\n";

     for(Counter=0;Counter<4;Counter++)
     {
          cout << setw(10) << (Counter + 1)
          << setw(10) << Quotients[Counter];

          cout << "\n";
     }

     NumberV = NumberV / 2;

     return(Manipulated);
}

C:\Documents and Settings\TOesterle\Desktop\PtrPractical\ptrpimp.cpp(61) : error C2556: 'void __cdecl DivideF(double &,double)' : overloaded function differs only by return type from 'double __cdecl DivideF(double &,double)'
        c:\documents and settings\toesterle\desktop\ptrpractical\ptrphead.h(20) : see declaration of 'DivideF'
C:\Documents and Settings\TOesterle\Desktop\PtrPractical\ptrpimp.cpp(61) : error C2371: 'DivideF' : redefinition; different basic types
        c:\documents and settings\toesterle\desktop\ptrpractical\ptrphead.h(20) : see declaration of 'DivideF'