SOLUTION: Two trucks leave the truck stop at the same time. One truck goes north, driving at an average speed that is 20kph slower than the truck driving east. After 12 min, the trucks are

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Question 1031576: Two trucks leave the truck stop at the same time. One truck goes north, driving at an average speed that is 20kph slower than the truck driving east. After 12 min, the trucks are 20 kilometers apart. Find the average speed of each truck.
Answer by josgarithmetic(39625) About Me  (Show Source):
You can put this solution on YOUR website!
             SPEED       TIME         DISTANCE

NORTHWARD     r-20       1%2F5         %28r-20%29%2F5

EASTWARD       r         1%2F5         r%2F5

SEPARATION                             20

The 12 minutes travel time is %281%2F5%29hour.

The north and east distances form the legs of a right triangle, making distance relationship
conforming to Pythagorean Theorem Formula.

highlight%28%28%28r-20%29%2F5%29%5E2%2B%28r%2F5%29%5E2=20%5E2%29
Solve this for r.