For layoffs not to be in violation of the ADEA, they must be across the board.

The two basic methods of proving a substance dangerous are:

a) animal testing and natural experiments. b) animal testing and epidemiological studies. c) computer models and epidemiological studies. d) computer models and natural experiments.

If one of Billy's machines breaks down, it usually results in about 6 hours of downtime. When this happens, Billy's profits are reduced by:

A) $15. B) $18. C) $25. D) $35.