Thread: Need help with a program that determines the miles per gallon for 3 tanks of gas

This seems to be a popular assignment. I'm most finished with it but I need to average the three readings and I'm not able to get the math to roll the right way.

Was hoping to get some help on how to finish this thing up.

Code:

#include <stdio.h>
int main (void)
{
    int input;
    int x;
    int counter = 0;
    float gallonsUsed, milesDriven, mpg;
    float total = 0;
    float avgMPG = 0;
    
    printf ("Welcome to the mileage calculator.\n");
    
    printf ("\n");

    printf ("This program will calculate the miles per gallon for you for three tanks of     gas after you have entered the gallons used and miles driven.\n");
    
    printf ("\n");    

    
    for ( x = 0; x < 3; x++ ) 
    {
        
        total = total + mpg;
        counter = counter + 1;
    
        printf ("Enter the number of gallons used for tank #%d: ", x + 1);
        scanf ("%f", &gallonsUsed);
        printf ("Enter the number of miles driven: ");
        scanf ("%f", &milesDriven);
    
        mpg = milesDriven / gallonsUsed; //mpg
        printf ("*** The miles per gallon for this tank is %.1f\n", mpg);
        getchar( );

        printf ("\n");    

    }

    avgMPG = (float) total / counter;
    printf ("Your overall average miles per gallon for three tanks is %.1f\n", avgMPG);

    printf ("\n");    
    
    printf ("Thank you for using the program. Goodbye.");

    printf ("\n");    
}

On line 23 how can you calculate total at this stage? What are the values of total and mpg?

I do admit that was me throwing something against the wall and it's wrong. The program still runs, but its not correct.

I'm totally new to this (as you can probably tell).

My teachers notes told us we need to do an accumulation of all three and get the average. I'm just not sure what that code is and how to work it in here.