Problema Solution
every morning on the way to work, Veronica drives at a constant speed on the highway, and it takes her 45 minutes. if she drove 8 miles per hour faster than she normally drives, the trip would only take her 40 minutes. how long would it take her if she drove 16 miles per hour faster than she normally drives?
Answer provided by our tutors
let
d = the distance Veronica drives
v = the speed that she normally drives
t1 = 45 min = 45/60 hr = 0.75 hr the time when she drives with constant speed v
t2 = 40 min = 40/60 = 2/3 hr the time when she drives with speed v + 8 (8 miles per hour faster than she normally)
t = the time when she drives with speed v + 16
since speed = distance/time follows distance = speed*time
v*t1 = (v + 8)*t2
0.75v = (v + 8)*(2/3)
by solving we find:
v = 64 mph
click here to see the step by step solution of the equation:
v + 16 = 64 + 16 = 80 mph
d = v*t1 = 64*0.75 = 48 mph
t = d/v
t = 48/80
t = 0.6 hr
t = 0.6*60 min
t = 36 min
if she drove 16 miles per hour faster than she normally drives it will take her 36 minutes.