Calculate admission prices of different days Children are admitted free on Sundays, and pay only $6 each, any other day
Adults admission is $12 any day, except on Tuesdays, when it is only $8 
Monday, Wednesday, Thursday, Friday, Saturday are same prices.
How do I shorten Mon/Wed-Sat so the code isn't repeated and can be single-line? 
Sunday and Tuesday prices vary.




#include &lt;iostream&gt; 
#include &lt;iomanip&gt;
using namespace std;

int main()
{
int Children, Adults, tickets, persons, pricea, pricec, total_price;
char day;

cout &lt;&lt; "Enter the number of Adults attending? ";
cin &gt;&gt; Adults;
cout &lt;&lt; "Enter the number of Children attending? ";
cin &gt;&gt; Children;
cout &lt;&lt; "What is the day of the week? ";
cin &gt;&gt; day;


cout &lt;&lt; "The day entered is: " &lt;&lt; day &lt;&lt; endl;
switch (day)
{
case 'm': case 'M':
    cout &lt;&lt; "Monday" &lt;&lt; endl;
    pricea = 12;
    pricec = 6;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
case 't': case 'T':
    cout &lt;&lt; "Tuesday" &lt;&lt; endl;
    pricea = 8;
    pricec = 6;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
case 'w': case 'W':
    cout &lt;&lt; "Wednesday" &lt;&lt; endl;
    pricea = 12;
    pricec = 6;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
case 'r': case 'R':
    cout &lt;&lt; "Thursday" &lt;&lt; endl;

    pricea = 12;

    pricec = 6;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
case 'f': case 'F':
    cout &lt;&lt; "Friday" &lt;&lt; endl;

    pricea = 12;

    pricec = 6;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
case 's': case 'S':
    cout &lt;&lt; "Saturday" &lt;&lt; endl;

    pricea = 12;

    pricec = 6;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
case 'u': case 'U':
    cout &lt;&lt; "Sunday" &lt;&lt; endl;
    pricea = 12;
    pricec = 0;
    total_price = (Adults*pricea) + (Children*pricec);
    cout &lt;&lt; "Total price is: " &lt;&lt; total_price &lt;&lt; endl;
    break;
default:
    cout &lt;&lt; "Not a valid day" &lt;&lt; endl;
}
system("pause");
return 0;
}
Several things that come to mind:


Don't use using namespace std; as it leads to namespace pollution (e.g. name collision)
Don't use std::endl unless you need to flush the buffer
As you already noticed there is a lot of duplicate code and just like DRY states we don't want to repeat ourselves


Going for a simple rewrite while keeping mostly to your original code we could do the following:

#include &lt;iostream&gt;

int main()
{
    unsigned int kids, adults;
    char day;

    std::cout &lt;&lt; "Enter the number of Adults attending? ";
    std::cin &gt;&gt; adults;

    std::cout &lt;&lt; "Enter the number of Children attending? ";
    std::cin &gt;&gt; kids;

    std::cout &lt;&lt; "What is the day of the week? ";
    std::cin &gt;&gt; day;
    std::cout &lt;&lt; "The day entered is: " &lt;&lt; day &lt;&lt; "\n";

    switch (day)
    {
        case 'u': case 'U':
            std::cout &lt;&lt; "Total price is: " &lt;&lt; adults * 12 &lt;&lt; "\n";
            break;

        case 't': case 'T':
            std::cout &lt;&lt; "Total price is: " &lt;&lt; adults * 8 + kids * 6 &lt;&lt; "\n";
            break;

        case 'm': case 'M':
        case 'w': case 'W':
        case 'r': case 'R':
        case 'f': case 'F':
        case 's': case 'S':
            std::cout &lt;&lt; "Total price is: " &lt;&lt; adults * 12 + kids * 6 &lt;&lt; "\n";
            break;

        default:
            std::cout &lt;&lt; "Not a valid day" &lt;&lt; "\n";
    }
}


This makes use of Fall through cases in the switch construct thus simplifying your code without overengineering it.