from math import gcd
from sys import stdin
t = int(input())

for i in range(t):
    n = int(stdin.readline())
    mas = []
    mas2 = []
    summ1 = 0
    summ2 = 0
    summ3 = 0
    maxx = 0
    for j in range(n):
        mas.append(list(map(int, stdin.readline().split())))
        mas[j].append(j+1)
    mas.sort(reverse = True)
    for k in mas:
        summ2 += k[1]
        summ3 += (k[0]*k[1])
    chisl, znam = summ3, summ2
    for p in range(n):
        summ1 += mas[p][0]
        a = chisl
        b = znam
        chisl = summ3+summ1
        znam = summ2+p+1
        if chisl/znam >= maxx:
            maxx = chisl/znam
            mas2.append(mas[p][2])
        else:
            break
    gcd1 = gcd(a, b)
    print(str(a//gcd1)+"/"+str(b//gcd1))
    print(p)
    print(" ".join([str(mas2[i]) for i in range(p)]))