Could REALLY use some help with this problem

Alawn mower manufacturer incurs a total of 34,816 in overhead costs and 388 per lawn mower in production costs. how many lawn mowers were manufactured if the average cost of productions is 660

Agreeting card company can produce a box of cards for $7.50. if the initial investment by the company was $50,000, how many boxes of cards must be produced before the average cost per box falls to $10.50?

Which approach to the theory-and-research cycle does the following sequence reflect: (1) specific observations suggest generalizations, (2) generalizations produce a tentative theory, (3) the theory is tested through the formation of hypotheses, and (4) hypotheses may provide suggestions for additional observations?