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sunman
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A train traveling at a certain constant speed takes 30 seconds longer to travel 2 kilometers than it would take to travel 4 kilometers at 120 kilometers per hour. At what speed, in kilometers per hour, is the train traveling?
A. 40
B. 48
C. 80
D. 96
E. 120
I selected B, but apparently the answer was C? I don't see it.
Work below:
120 kph for 4 km =
120 kph / 60 minutes = 2 kpm (km per minute)
@ 4 km = 2 minutes
The train takes 30 seconds longer to travel 2km than it does to travel 4km, so:
Time = 2:30
Distance = 2km
2km/2.5 minutes = 0.8 minutes per km
0.8 x 60 minutes = 48 km.
Why is the answer 80? Please help.
A. 40
B. 48
C. 80
D. 96
E. 120
I selected B, but apparently the answer was C? I don't see it.
Work below:
120 kph for 4 km =
120 kph / 60 minutes = 2 kpm (km per minute)
@ 4 km = 2 minutes
The train takes 30 seconds longer to travel 2km than it does to travel 4km, so:
Time = 2:30
Distance = 2km
2km/2.5 minutes = 0.8 minutes per km
0.8 x 60 minutes = 48 km.
Why is the answer 80? Please help.
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