# #3 - Setting Up Equations for Given Situations

### Sample Question:

3. When getting into shape by exercising, the subject’s maximum recommended number of heartbeats per minute (h) can be determined by subtracting the subject’s age (a) from 220 and then taking 75% of that value. This relation is expressed by which of the following formulas?

A. $$h = .75(220 - a)$$

B. $$h = .75(220) - a$$

C. $$h = 220 - .75a$$

D. $$75h = 220 - a$$

E. $$220 = 75(h - a)$$