Question

Two runners start 30 kilometers apart and run toward each other. They meet after 3 hours. One runner runs 2 kilometers per hour faster than the other runner. What rate do they run?


A.2 km/hr and 4 km/hr
B.3 km/hr and 5 km/hr
C.5 km/hr and 7 km/hr
D.4 km/hr and 6 km/hr

Answer 1

A. 30/(2+4) = 30/6 = 5 -- Too slow!
B. 30/(3+5) = 30/8 = 3.75 -- Too slow!
C. 30/(5+7) = 30/12 = 2.5 -- Too fast!
D, 30/(4+6) = 30/10 = 3 -- Just right.

Answer 2

Thanks

Answer 3

Running directly toward each other, we can just add the rates and cover the distance, ANY other arrangement and it takes more work.

Answer 4

so the answer is D?