def earlier_name(name1: str, name2: str) -> str:
    """Return the name, name1 or name2, that comes first
    alphabetically.

    >>> earlier_name('Jen', 'Paul')
    'Jen'
    >>> earlier_name('Colin', 'Colin')
    'Colin'
    """
    
    if name1 > name2:
        return name2
    #else:    don't need else because there is only
    # one other option
    return name1


def ticket_price(age: int) -> float:
    """Return the ticket price for a person with age in years.
    Seniors 65 and over pay 4.75, kids 12 and under pay 4.25 and
    everyone else pays 7.50.

    Precondition: age > 0
    
    >>> ticket_price(7)
    4.25
    >>> ticket_price(21)
    7.5
    >>> ticket_price(101)
    4.75
    """
    
    if age >= 65:
        return 4.75
    elif age <= 12:
        return 4.25
    else:
        return 7.5


def format_name(first: str, last: str) -> str:
    """Return the given first and last name as a single string, in the form:
    last_name, first_name
    where last_name and first_name are replaced by last and first.
    Mononymous persons (those with no last name) should have their name
    returned without a comma.

    >>> format_name('Cherilyn', 'Sarkisian')
    'Sarkisian, Cherilyn'
    >>> format_name('Cher', '')
    'Cher'
    """
    
    if last == '':   # len(last) == 0
        return first
    return last + ', ' + first