Question

After the football game, the traffic out of the school parking lot is horrible! In fact, since the school is set off from town, the slow moving line of cars snakes back into town, bumper to bumper. The distance your car is from home is a linear function. When you have been crawling along for 10 minutes, you are 11 km from home, and when you have been driving for 15 minutes, you are 8 km from home. When (in minutes) will you reach home?

Answer 1

you have 2 points (10, 11) and (15,8) of the form (time, distance) or (t,d)
slope = (8-11)/(15-10) = -3/5

d - 11 = (-3/5)(t - 10)

so when you are home, d = 0
0-11 = (-3/5)t + 6
(3/5)t = 17
t = .....

Answer 2

Stated somewhat more simply: It took you 5 minutes to go 3 kilometers. How many kilometers do you have left to go? Divide that by 3 and multiply that by 5.

Or, as Richard Bach wrote in "Illusions, the Adventures of a Reluctant Messiah,"
>Everything in this book may be wrong.<