#include<iostream> #include<cstdio> using namespace std; int main() { double a=5,b=8,c=12,d=39; printf("%.3lf",(a+b+c)/3); printf("%lf",d/a,d///a%); printf("%lf",d/b,d///b%); printf("%lf",d/c,d///c%); return 0; }