#include<stdio.h>
#include<math.h>
int main()
{
  double avgCallLength = 40,timeInitial = 1,increment = 1,timeFinal = 10;
  
  
  
  while( timeInitial <= timeFinal)
  {
    
    double prob = 1 - pow(2.71828,(0-timeInitial)/avgCallLength);
       
    
      printf(" Probability of a call lasting less than %lf min is %lf   \n",timeInitial,prob);
      timeInitial = timeInitial + increment;
    
  }
  return 0;
}