Question

The time, t, required to drive a certain distance varies inversely with the speed, r. If it takes 7 hours to drive the distance at 55 miles per hour, how long will it take to drive the same distance at 65 miles per hour?

Answer 1

Answer: Approximately 5.92 hours

=========================================================

Step-by-step explanation:

Since the time varies inversely with the speed, this means they multiply together to get some constant, which this case it would be the distance.

distance = speed*time

d = r*t

-------------

Now plug in r = 55 and t = 7

d = r*t

d = 55*7

d = 385

The distance is 385 miles.

--------------

Plug in d = 385 and r = 65, solve for t.

d = r*t

385 = 65*t

t = 385/65

t = 5.92 approximately

It takes about 5.92 hours to drive the distance of 385 miles at a speed of 65 mph.