Time varies inversely with speed if the distance is constant. It takes James 4 hours to get to his destination when he travels at 65 miles per hour. How many minutes would he have saved if he drove the same distance 15 per hour faster?

Step-by-step explanation:

Time varies inversely with speed if the distance is constant. This means that if speed increases, the time it will take to cover the same distance will reduce

t = k/s

Where t = time

k = constant of inverse proportionality

s = speed

It takes James 4 hours to get to his destination when he travels at 65 miles per hour

4 = k/65

k = 65*4 = 260

t = 260/s

If he drove 15 miles / hour faster, the new speed is 65 + 15 = 80miles/hour.

The time it will take him is

t = 260/s

t = 260/80 = 3.25 hours

The amount of time he would save is

4 hours - 3.25 hours = 0.75 hours

Converting 0.75 hours to minutes, we multiply by 60

Amount if time saved in minutes = 0.75*60 = 45 minutes