Question

The time t required to drive a certain distance varies inversely with the speed r. If it takes 2 hours to drive the distance at 30 miles per hour, how long will it take to drive the same distance at 35 miles per hour?

Answer 1

t = k /r where k is a constant
plugging in given values
2 = k / 30 so k = 60

so we have the relation t = 60 / r

when r = 35

t = 60 / 35 = 1.71 hours answer