c Divide the cost of the speeding ticket with the time saved.
A
a 37.5 minutes
B
b ≈ 46 minutes
C
c ≈ $23.50 per minute
Practice makes perfect
a The distance traveled d during a certain time t and with a given speed r can be calculated by using the following formula.
d=rtFrom the exercise, we know that Lettie drives with a speed of 80 mph and that she travels 50 miles. By substituting these values into the exercise, we can solve for t.
It takes her 0.625 hours to travel the given distance at the speed at which she is driving. If we want this number in minutes, we must multiply by 60.
0.625* 60 = 37.5minutes
b Let's repeat the calculations from Part A, but switch the speed from 80 to 65.
It takes her 0.769 hours to travel the given distance at the speed limit. Again, to get this number in minutes, we must multiply by 60.
0.769* 60 ≈ 46minutes
c Let's restate the times it took to travel with the different speeds.
80 mph:& 37.5 minutes
65 mph:& 46 minutes
As we can see, Lettie saved 8.5 minutes by going faster. To calculate the fine per minute, we have to divide the amount of the fine with the total number of minutes she saved.
$200/8.5≈ $23.50
She paid $23.50 for every minute she saved.
