​​Suppose a car drives $30$ miles an hour for $2$ hours, 40 miles an hour for one hour, and $50$ miles an hour for half an hour. 

1. ​How far does the car travel?

   Step (a):

   $30 \frac { mi } { h } \cdot 2 h + 40 \frac { mi } { h } \cdot 0.5 h$

2. What is the car’s average speed?

   Hint (b):

   $\text { average speed } = \frac {\text { total distance }} {\text { total time }}$