jeffreyleo
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- May 2, 2022
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Question is a 240 metre long train overtake a man walking at 3km/hour in the same direction. It takes train 9 seconds to overtake the man. Ask what is train's speed.
suppose train speed is x km/hour, then
The standard answer is distance travelled=train length 0.24=(x-3)*9/3600, and answer is 0.24=9x/3600-27/3600. 864=9x-27, x=99
However, as the man is also walking, shouldn't we add up whatever the distance man walks and put the formula as 0.24+3*9/3600=(x-3)*9/3600, and the answer becomes 864+27=9x-27, 9x=918, x=102.
Thanks for your help
suppose train speed is x km/hour, then
The standard answer is distance travelled=train length 0.24=(x-3)*9/3600, and answer is 0.24=9x/3600-27/3600. 864=9x-27, x=99
However, as the man is also walking, shouldn't we add up whatever the distance man walks and put the formula as 0.24+3*9/3600=(x-3)*9/3600, and the answer becomes 864+27=9x-27, 9x=918, x=102.
Thanks for your help