Question

Raj gets 1.5 mile head start and runs at a rate of 4.5 miles per hour.Jacinda's progress is represented by a graph that goes through the points (1,10), (2,20), (3,30). How long will Jacinda need to run to catch up with Raj?

Answer 1

Jacinda:  d = 10 * t  ( a rate: 10 miles per hour )
Raj :  d = 1.5 + 4.5 * t
Jacinda will catch up with Raj when:
10 t = 1.5 + 4.5 t
10 t - 4.5 t = 1.5
5.5 t = 1.5
t = 1.5 : 5.5 = 0.27 hours = 16.2 min  =  16 min 12 seconds