if statement fall through output issues - c++

Question

whenever I enter a different case and enter an hour that meets the if statements requirements the else also gets printed, help I just need one output from each different situation.
the example below is the error I get.
ex: enter 'a' enter '11' output 'the amount due is 11.95' 'the amount due is 9.95'
//Libraries
#include <iostream>
#include <iomanip>
#include <cstdlib>
using namespace std;
//Global Constants
//Functioning Prototypes
//Execution Begins here
int main(int argc, char *argv[]){
//Declare Variables
char pack;
int hours;
float due;
//prompt user
cout<<"Please choose one monthly internet subscription package: a, b, or c\n";
cin>>pack;
cout<<"Enter how many hours were that month used\n";
cin>>hours;
//process
cout<<setprecision(2)<<fixed<<showpoint;
switch (pack){
case 'a':
if (hours>=10 && hours<=744){
hours=(hours-10)*2;
due=hours;
due+=9.95;
cout<<"The amount due is $"<<due<<endl;
}
else if (hours>=744){
cout<<"ERROR: a month cannot exceed 744 hours\n";
}
else ( hours<=10);{
due=9.95;
cout<<"The amount due is $"<<due<<endl;
}
break;
case 'b':
if (hours>20 && hours<744){
hours=(hours-20);
due=hours;
due+=14.95;
cout<<"The amount due is $"<<due<<endl;
}
else if (hours>=744){
cout<<"ERROR: a month cannot exceed 744 hours\n";
}
else (hours<=20);{
due=14.95;
cout<<"The amount due is $"<<due<<endl;
}
break;
case 'c':
if (hours>=744){
cout<<"ERROR: a month cannot exceed 744 hours\n";
}
else if (hours<744);{
due=19.95;
cout<<"The amount due is $"<<due<<endl;
}
break;
}
system("PAUSE");
return 0;
}

Answer 1

else (hours<=20);{
due=14.95;
cout<<"The amount due is $"<<due<<endl;
}
is equivalent to:
else (hours<=20) {
//Do nothing
}
{
due=14.95;
cout<<"The amount due is $"<<due<<endl;
}
You need to remove the ";". Otherwise, the last code block will always be executed because it isn't part of the else block.