def age_bin(age, labels, bins):
    """ Return a label for a given age and bin.
    
    Argument notes:
    age -- int
    labels -- list of strings
    bins -- list of tuples, with the first tuple value being 
            the inclusive lower limit, and the higher tuple 
            value being the exclusive upper limit
    """
    for x in range(len(bins)):
        if age < bins[x][1] and age >= bins[x][0]:
            return labels[x]