Question

1) An aircraft flying at 500 km/h completes a journey in 8.4 h. How long would the journey take if it flew at a speed of 420 km/h?

2) Jackie can drive to work in 18 mins if he travels at an average speed of 35 m.p.h. How long will the journey take if she drives at an average speed of 45 m.p.h.?

Answer 1

#1
Recall that rate is distance traveled over time.
r = d/t
or solving for distance,
d = rt

We can therefore write the proportion as
(rate1)*(time1) = (rate2)*(time2)
(500)*(8.4) = (420)*(time2)

Now solve for time2. Units in hours.

#2
Same what you'll do here in #2.
(rate1)*(time1) = (rate2)*(time2)
(35)*(18) = (45)*(time2)

Now solve for time2. Units in minutes.

Hope this helps~ `u`

Answer 2

Thnx