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If two trains ,travelling at a speed of 72mph and 48 mph respectively,
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22 Apr 2021, 06:46
22 Apr 2021, 06:46
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83% (01:27) correct
16% (01:12) wrong based on 42 sessions
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If two trains ,travelling at a speed of 72mph and 48 mph respectively, are approaching each other from opposite direction; what is the distance between them 1 minute before the collision ?
A)2 miles
B)3 miles
C)4 miles
D)5 miles
E)none of the above.
A)2 miles
B)3 miles
C)4 miles
D)5 miles
E)none of the above.
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Re: If two trains ,travelling at a speed of 72mph and 48 mph respectively,
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22 Apr 2021, 08:43
22 Apr 2021, 08:43
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Carcass wrote:
If two trains ,travelling at a speed of 72mph and 48 mph respectively, are approaching each other from opposite direction; what is the distance between them 1 minute before the collision ?
A)2 miles
B)3 miles
C)4 miles
D)5 miles
E)none of the above.
A)2 miles
B)3 miles
C)4 miles
D)5 miles
E)none of the above.
I call this a shrinking gap question.
When we ADD the speeds of the trains, we get 72 mph + 48 mph = 120 mph
This means, the gap SHRINKS at a rate of 120 miles per HOUR
We can also say that the gap SHRINKS at a rate of 2 miles per MINUTE
What is the distance between them 1 minute before the collision ?
Since the gap SHRINKS at a rate of 2 miles per MINUTE, we can conclude that, 1 minute before the collision, the trains will be 2 miles apart.
Answer: A
General Discussion
Re: If two trains ,travelling at a speed of 72mph and 48 mph respectively,
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21 Jun 2024, 05:22
21 Jun 2024, 05:22
1
Let distance between them 1 minute before collision be x
Sum of their speeds = 72 + 48 = 120
Therefore 1/60 = x/120
x = 2 miles
Answer A.
Adewale Fasipe, quant instructor from Lagos Nigeria.
Sum of their speeds = 72 + 48 = 120
Therefore 1/60 = x/120
x = 2 miles
Answer A.
Adewale Fasipe, quant instructor from Lagos Nigeria.
