SOLUTION: One person travels north at the rate of 4 kilometers per 30 minutes. The other travels east at a rate of 1 kilometer more than the first persons rate over 10 fewer minutes. After a

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Question 908873: One person travels north at the rate of 4 kilometers per 30 minutes. The other travels east at a rate of 1 kilometer more than the first persons rate over 10 fewer minutes. After a while they called each other and at that time the shortest distance between them was 6.8 kilometers. How many minutes after they departed was this phone call made?
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
One person travels north at the rate of 4 kilometers per 30 minutes. The other travels east at a rate of 1 kilometer more than the first persons rate over 10 fewer minutes. After a while they called each other and at that time the shortest distance between them was 6.8 kilometers. How many minutes after they departed was this phone call made?
One person travels north at the rate of 4 kilometers per 30 minutes.
= 8 km/h


The other travels east at a rate of 1 kilometer more than the first persons rate over 10 fewer minutes.
5 km in 20 minutes
15km/h
The time taken by both is the same
d=rt
the distances traveled by them are
8t & 15t
They are travelling at right angles
using Pythagoras theorem
(8t)^2+(15t)^2= (6.8)^2
64t^2+225t^2=46.24
289t^2= 46.24
t^2= 46.24/289
t^2=0.16
t=0.4 hours
0.4 * 60 = 24 minutes


they called each other after 24 minutes