import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int n = sc.nextInt(); while(n-- > 0) { int m = sc.nextInt(); int gradeSum = 0; float scoreSum = 0; for(int i = 0; i < m; i++) { int a = sc.nextInt(); double b = sc.nextDouble(); gradeSum += a; scoreSum += a * b; } System.out.println(gradeSum + " " + Math.round(scoreSum*10/gradeSum)/10.0); } } }