These questions are pertaining to rate, time and distance

Question

At 9:00 am Linda leaves work on a business trip, gets on the interstate, and sets her cruise control at 60mph. At 9:30 am, Bruce notices she's left her briefcase and cell phone, and immediately starts after her driving 90mph. At what time will Bruce catch up with Linda?

 

a) What is the equation you will use to solve this problem?

b) What is the answer to this problem?

Answer 1

Let t= time
speed = distance /time

distance =speed*time

let time taken by Bruce =t
Linda left 30 mins before Bruce

so time taken by Linda = (t+0.5)

 

For Linda

 

distance =60(t+0.5)

 

For Bruce

 

distance =90 t

 

As both cover same distance

60(t+0.5) = 90t 

60t + 30 = 90t

30 = 90t - 60t

30 = 30t

 

1=t

t = 1 hours

 

So Bruce catch up Linda after 1 hr means at 10.30 am