백준 10984 내 학점을 구해줘

B_10984.java

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);
        }
    }	
}