Let t be the time.
Since Julie's and the escalator's rates are on opposite directions, we can represent it as one of them (+) and the other (-).
Rate is distance traveled over time, or
r = d/t
or solving for d,
d = r*t
Then we write the equation:
(Julie's distance) - (Escalator distance) = (Distance of one level)
96*t - 64*t = 48
32t = 48
t = 1.5 minutes
Hope this helps~ `u`
An escalator in a department store moves down at the rate of 64 steps per minute. Julie can walk fast up ordinary steps at the rate of 96 steps per minute. In the store, there are 48 steps from one level to another. Julie decides to walk fast up the down escalator. How long in seconds will it take her to go up one level?
2 answers
90 seconds
2 answers