In a 1000 m linear race, X beats Y by 100 m or 10 seconds. What is the difference between the speed of X and Y in m/s?
Answer
Correct Answer : b ) 10/9
Explanation :In the question, X beats Y by 100 m or 10 seconds.
It means X is at the finish line and Y is 100 m behind or Y reaches the finish line 10 seconds after X or it can be said that Y will cover the 100 m of distance in 10 seconds.
The whole situation can be depicted in the diagram below:
The speed of Y = 100m/10 s = 10 m/s
Time taken by Y to cover 900 m = 900/10 = 90 seconds
In 90 seconds, X covers 1000 meters
Speed of X = 1000/90 = 100/9 m/s
The difference in speed of X and Y = 100/9 - 10 = 10/9 m/s
Hence, (b) is the correct answer.
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