Chapter 8, Problem 3STP

To determine

To find: rate of change of B

Answer to Problem 3STP

The correct option is C

Explanation of Solution

Given:

B covers distance of 360 feet after 20 seconds

She travel 1080 feet in one minute.

A 18 feet per minute

B 16 feet per minute

C 18 feet per second

D 16 feet per second

Calculation:

Now, make the table that shows the relation between time and distance cover by Bethany.

Time (seconds) [x]	Distance (feet) [y]
20	360
60	1080

The rate of change is change in one quantity with respect to another quantity.

Thus, the rate of change is change in distance with respect to change in time.

So,

  $\begin{array}{c}\text{Rate of change}=\frac{1080-360}{60-20}\\ =\frac{720}{40}\\ =18\end{array}$

Hence, rate of change is increase of 18 feet per second

Conclusion:

Therefore, the correct option is C