Question

谜语题。
1. Upon leaving a cafe,one boy paid his bill,while his friend handed the cashier a slip of paper with
    the number 100480 on it. The cashier snuled and let him leave without paying. Why?
    Answer: _                                                           .
2. What can pierce(打孔) one's ears without a hole?
    Answer: _                                                           .

Answer 1

1. 1004180 means "I owe nothing;for I ate nothing".
2. Noise