SOLUTION: John started walking East at 10:00 AM at a rate of 2 km/hr. James stated walking South at 10:30 AM at a rate of 4km/hr. What time is it when they are 5 km apart?

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Question 596745: John started walking East at 10:00 AM at a rate of 2 km/hr. James stated walking South at 10:30 AM at a rate of 4km/hr. What time is it when they are 5 km apart?
D (x) = Rate x time

Tried formula below, but stuck on time part????
a2 + b2 = c2 so 4x2 + 2x2 = 25
x= 1.25

Answer by solver91311(24713) (Show Source):
You can put this solution on YOUR website!

At 10:30 when James starts, John will be 30 minutes into his trip. 30 minutes at 2 km/hr is 1 km. One hour later John will be 3 km from the start and James will be 4 km from the start, making a 3-4-5 right triangle at time 11:30.

That was the easy way. Now the hard way:

In the first 30 minutes John goes 1 km. Every hour after that, he goes 2 km. So counting hours since JAMES starts, John goes km. James is going twice as fast as John, so every hour after James starts he goes km.

In order for them to be 5 km apart:

Simplifying:

Solve for the . Toss out the negative value (you don't care what happened before either of them started the trip, do you?)

John

My calculator said it, I believe it, that settles it