#!/usr/bin/env python
for t in range(int(input())):
    n = int(input())
    w, l = list(map(int, input().split())), list(map(int, input().split()))
    last, result, frogs = -1, 0, sorted(zip(w, range(n), l))
    for weight, position, length in frogs:
        hits = 0 if position > last else (last-position)//length + 1
        last = position + hits*length
        result += hits
    print(result)