Question

41) A man in a train notices that he can count 31 poles
in one minute. If they are known to be 50metres
apart, then at what speed is the train travelling?
A. 55 kmph
B. 57 kmph
C. 75 kmph
D. 63 kmph​

Answer 1

Answer:

• At 90 kmph speed is the train travelling.

Step-by-step explanation:

Given that:

• Total number of poles = 31
• Total time = 1 minute
• Distance between two poles = 50 m

To Find:

• At what speed is the train travelling?

First finding the total distance:

• Number of gaps between two poles = (2 - 1) = 1
• Number of gaps between 31 poles = (31 - 1) = 30

• Distance between two poles = 50 m
• Distance between 31 poles = (30 × 50) m
• Distance between 31 poles = 1500 m

Converting the distance of 1500 m into km:

• 1 m = 1/1000 km
• 1500 m = 1500/1000 = 3/2 km

Converting the time of 1 minute into hour:

• 1 minute = 1/60 hour

Now, We have:

• Total distance = 3/2 km
• Total time = 1/60 hour

Formula used:

• Speed = Distance / Time

Finding the speed of train:

• Speed of train = (3/2) / (1/60) km/hr
• Speed of train = (3 × 60)/(1 × 2) km/hr
• Speed of train = 90 km/hr

Answer 2

Given :-

• Total number of poles = 31
• Total time = 1 minute
• Distance between two poles = 50 m

To Find :-

• Speed of the Train.

Solution :-

⟼ Distance between two poles = 50 m

⟼ Distance between 31 poles = (30 × 50) m

⟼ Distance between 31 poles = 1500 m

❍ Converting the distance of 1500 m into km:

• 1 m = 1/1000 km
• 1500 m = 1500/1000 = 1.5 km

❍ Converting the time of 1 minute into hour:

• 1 minute = 1/60 hour

________________

We know that :

✶ Speed = Distance / Time

⟾ Speed of train = 1.5/ (1/60) km/hr

⟾ Speed of train = 1.5 × 60 km/hr

⟾ Speed of train = 90 km/hr

Thus, Speed of the Train is 90km/hr

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