Number always missing decimals after calculation - c++

Question

Sorry if this is summarized wrong and etc.. This is my first time asking a question on Stackoverflow, so if I'm making any mistakes, let me know.
Problem:
In line 20, code embedded below, I'm performing a calculation, more specifically this calculation: 11 * 50 / 100, which if I'm not mistaken should give a result of 5.5. But my console gives me a result of 5. Maybe it's because it's late, but I personally can't see a thing wrong in that line.
Or let me know if I'm using cout wrong.
Explanation of program:
You receive an input of five ages, a ticket cost 10, which results in 50. But you may substract the youngest persons age as percent from the final price.
Kind regards Olle!
using namespace std;
int main() {
int ages[5] = {11,18,19,30,34};
int ticketPrice = 10;
/*for (int i = 0; i < 5; ++i) {
cin >> ages[i];
}*/
int agesSize = *(&ages + 1) - ages;
int finalPriceWithoutDiscount = ticketPrice * agesSize;
int min;
min = ages[0];
for(int i=0;i< agesSize; i++){
if(ages[i] < min ){
min = ages[i];
}
}
double discount= min * finalPriceWithoutDiscount / 100;
cout << discount << endl;
// expected output from values:[min=11, fPWD = 50]
// 5.5
// actual output:
// 5.00000
double truePrice = finalPriceWithoutDiscount - discount;
cout << std::fixed << truePrice;
// my output:
// 45.00000
return 0;
}

Answer 1

In your calculation of discount, all operands (min, finalPriceWithoutDiscount and 100) are of type int. The operations performed are therefore integer operations. No decimals are produced.
The (integral) result of the calculation is then assigned to a floating point variable, and thus converted to floating point. But that happens after the computation has been performed in the integer domain.
To fix this problem, cast at least one of your operands to double. Or rather, since you’re using a literal (100), use a floating point literal:
double discount = min * finalPriceWithoutDiscount / 100.0;
This causes the operation involving 100.0 (that is, the division) to be performed on floating point numbers instead of integers.

Answer 2

The other answer actually answers your question, but I thought I'd contribute a more C++ example:
#include <algorithm>
#include <iomanip>
#include <iostream>
#include <vector>
int main() {
std::vector<int> ages{11, 18, 19, 30, 34};
int ticketPrice = 10;
/*for (int i = 0; i < 5; ++i) {
cin >> ages[i];
}*/
int finalPriceWithoutDiscount = ticketPrice * ages.size();
int min = *std::min_element(ages.begin(), ages.end());
// Fix the calculation by using a double, 100.0
double discount = min * finalPriceWithoutDiscount / 100.0;
std::cout << discount << '\n';
// Fix by casting to double
double truePrice = static_cast<double>(finalPriceWithoutDiscount) - discount;
std::cout << std::fixed << truePrice;
return 0;
}