In this question output should be 5 as we are using "using namespace"..why it comes 10??

Question

https://code.sololearn.com/c60i3t3nTebp/?ref=app

Answer 1

This is not how you call a namespace
It would be like

namespace n1{
int x = 5;
}
int main(){
std::cout << n1::x;
}

Answer 2

Okay