'''
Created on Jul 23, 2013

@author: Jared
'''

# file input
file = open("plunder.in", "r")

# number of cases
cases = int(file.readline())

# each case
for c in range(cases):

    # Not used in python version.
    num_vendors = int(file.readline())

    # Parse out lists.
    temp = file.readline().split()
    list_quality = [float(x) for x in temp]
    temp = file.readline().split()
    list_worms = [int(x) for x in temp]
    n = len(list_quality)
    
    # Sum up the worms and quality so we can figure out average.
    sum_worms = 0
    sum_quality = 0
    for i in range(n):
        sum_quality += (list_quality[i]*list_worms[i])
        sum_worms += list_worms[i]

    # Calculate the average.
    avg = sum_quality/sum_worms

    # Go back and figure out which stands had above average worms and add!
    taken = 0
    for i in range(n):
        if list_quality[i] > avg + .000001:
            taken += list_worms[i]

    # Here is our result.
    print(taken)

# Close the file
file.close()