Question

An airplane leaves the airport at 2 pm and travels 650 mph to its destination. A second plane leaves at 6 pm and travels 800 mph. How long before the second plane reaches the same distance as the first plane?

Answer 1

(mph will be m/h)

P1 at 2pm rate of 650m/h
P2 at 6pm rate of 800m/h
difference of 4 hrs, means 4 hrs x 650m/h = 2600miles difference when P2 leaves.

assuming both planes are instantaneously at their speeds...

800m/h = 2600miles + 650m/h
-650m/h. -650m/h
150m/h = 2600miles
÷150. ÷150
=17.33 hours

= 17 hours and 20 minutes. This is putting 2 linear equations equal to each other.