getting a wrong answer

#include
#include
using namespace std;
int main()
{
int x;float b,t;
cin>>x;
cin>>b;
if((x<b)&&(x%5==0))
{
t = b-x-0.5;
cout<<fixed<<setprecision(2)<<t;
}
else
{
cout<<fixed<<setprecision(2)<<b;
}
return 0;
}

Always give link of question when asking.

if((x< b)&&(x%5==0))

Wrong. This allows b to be negative. You must check if theres enough money in bank account after the taxes + withdrawal.