Question

the time T required to drive a certain distance varies inversely with the speed, r. If it takes 4 hours to drive the distance at 40 miles per hour, how long will it take to drive the same distance at 55 MPH A. 2.91 B. 160.00 C. 22.00 D. 5.50

Answer 1

Hello,

Answer A

d :the distance in miles
t: the time in hours
v: the speed in miles/hours (vistesse)


d=v*t 
==>d=40*4=160(mi)

d=55*x=160==>x=160/55=2.909090... (mi/(mi/h)=h)≈2.91(hours)