well this is what my program does:

//asks for input for number of gallons
enter the gallons of gas used (-1 to end):

//asks for input for number of miles
enter miles driven:

//then shows the miles / gallon for this tank
the miles / gallon for this tank was ...

it loops this untill the user presses -1
then i want it to find out the avg of all the miles/gallons.

problem is that avg is over written every time the loop starts
here is the code for the program.

#include <iostream.h>
#include <conio.h>

float gal;
float avg;
void gas();
//void totalavg();
void main()
{
        while(gal>=0)
        gas();
        getch();
}

void gas()
    {
        float miles;

        cout <<"enter the gallons of gas used (-1 to end): "; 
        cin  >> gal;
        if(gal!=-1)
        {
        cout <<"enter miles driven: ";
        cin  >> miles;
        avg=miles/gal;
        cout <<"the miles / gallon for this tank was "<<avg<<endl;
        cout<<"\n";
        }   
    }

i think i need avg to be a array.

anyhelp or hints to this problem would be greatly apprecaited.

Are you still working on this or did you figure it out?

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