# #4 - Setting Up Equations for Given Situations

### Sample Question:

4. An airplane flew for 8 hours at an airspeed of x miles per hour (mph), and for 7 more hours at 325 mph. If the average airspeed for the entire flight was 350 mph, which of the following equations could be used to find x ?

A. $$x + 325 = 2(350)$$

B. $$x + 7(325) = 15(350)$$

C. $$8x - 7(325) = 350$$

D. $$8x + 7(325) = 2(350)$$

E. $$8x + 7(325) = 15(350)$$