Question

HI I can't quite seem to figure out how to code this please help :)

When assessing the quality of indoor air in office buildings, three types of pollutants are of con- cern; Total Volatile Organic Chemicals (TVOC), Polar Volatile Organic Chemicals (PVOC), and Respirable Particulate Matter (RPM). If all of the TVOC, PVOC, and RPM levels are below 300, 120, 60 μg/m3, respectively, the air quality is considered to be acceptable. If any of the TVOC, PVOC, and RPM levels are in excess of 500, 200, or 90 μg/m3, respectively, the air quality is considered to be unacceptable. Otherwise the air quality is considered to be marginal.

Write a computer program, air.c, which reads the concentrations of TVOC, PVOC, and RPM from the keyboard and reports the air quality to an output file.

For marking purposes, run your program 3 times using the values shown in the following table, and report the results for all three runs.

     TVOC        PVOC       RPM
     ----------------------------------
     245         113         60
     419         236         80
     119         105         52

Sample output is as follows;

TVOC concentration = 580
PVOC concentration =  60
RPM  concentration = 130
Air quality is unacceptable.

Answer 1

Answer

Code

#include <stdio.h>
#include <stdlib.h>
int main(){
   int tvoc,pvoc,rpm;   //variables to represent pollutants
   FILE *fp;   //pointer to file
  
   printf("Enter the concentration of TVOC pollutant: ");   //display the message
   scanf("%d",&tvoc);   //read the concentration of TVOC from the keyboard
   printf("Enter the concentration of PVOC pollutant: ");   //display the message
   scanf("%d",&pvoc);   //read the concentration of PVOC from the keyboard
   printf("Enter the concentration of RPM pollutant: ");   //display the message
   scanf("%d",&rpm);   //read the concentration of RPM from the keyboard
  
   fp = fopen("output.txt","a+");   //open the file
   /* exit the program if file pointer returns null */
   if(fp == NULL){
       printf("Error!");   
       exit(1);
   }
   /* If all of the TVOC, PVOC, and RPM levels are below
   300, 120, 60 µg/m3, the air quality is acceptable. */
   if((tvoc < 300) && (pvoc < 120) && (rpm < 60)){
       fprintf(fp, "TVOC concentration = %d\n", tvoc);   //write the TVOC concentration to the file
       fprintf(fp, "PVOC concentration = %d\n", pvoc);   //write the PVOC concentration to the file
       fprintf(fp, "RPM concentration = %d\n", rpm);   //write the RPM concentration to the file
       fprintf(fp, "Air quality is acceptable.\n\n");   //write message to the file
   }
   /* If any of the TVOC, PVOC, and RPM levels are in excess of
   500, 200, or 90 µg/m3, the air quality is unacceptable. */
   else if((tvoc > 500) || (pvoc > 200) || (rpm > 90)){
       fprintf(fp, "TVOC concentration = %d\n", tvoc);   //write the TVOC concentration to the file
       fprintf(fp, "PVOC concentration = %d\n", pvoc);   //write the PVOC concentration to the file
       fprintf(fp, "RPM concentration = %d\n", rpm);   //write the RPM concentration to the file
       fprintf(fp, "Air quality is unacceptable.\n\n");   //write message to the file
   }
   else{
       fprintf(fp, "TVOC concentration = %d\n", tvoc);   //write the TVOC concentration to the file
       fprintf(fp, "PVOC concentration = %d\n", pvoc);   //write the PVOC concentration to the file
       fprintf(fp, "RPM concentration = %d\n", rpm);   //write the RPM concentration to the file
       fprintf(fp, "Air quality is marginal.\n\n");   //write message to the file
   }
   fclose(fp);   //close the file  
   return 0;
}

Code Screenshots

Sample Output after First Run

Sample Output after Second Run

Sample Output after Third Run

Note - Please comment for any query.