Question

The Chang family is on their way home from a cross-country road trip.

​During the trip, the function D(t)=2,280-60t can be used to model their ​distance, in miles, from home after t hours of driving.
​​Part A:
Find D(15) and interpret the meaning in the context of the problem.

Answer 1

To find D(15), we simply substitute t = 15 into the function:

D(15) = 2,280 - 60(15)

D(15) = 2,280 - 900

D(15) = 1,380

Therefore, when the Chang family has been driving for 15 hours, they are 1,380 miles away from home.

Interpreting this result in the context of the problem, we can say that the family has made good progress on their trip and has covered a distance of 1,380 miles from home.