A school has 1800 students 55 %of the students of girls. how many boys are in the school?
1 answer:
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The length of train is 120 meters
The speed of train is 25 meter per second
<u><em>Solution:</em></u>
The speed is given by formula:
Given that,
It takes a train 60 seconds to completely drive through a bridge of 1260 m
And 90 seconds to completely drive through a tunnel of 2010 m
Let the length of the train be "x"
<em><u>The total distance travelled by the train across the bridge is given by:</u></em>
total distance = x + 1260 + x = 2x + 1260
[ here we use x + x to represent that train completely drives through bridge ]
The time taken is given as 60 seconds
<em><u>Therefore, the speed is given as:</u></em>
<em><u>The total distance travelled by the train through the tunnel is given by:</u></em>
total distance = x + 2010 + x = 2x + 2010
The time taken is given as 90 seconds
<em><u>Therefore, the speed is given as:</u></em>
The speed of the train was the same in both cases.
Equate both speeds
Thus length of train is 120 meters
<em><u>Find the speed of train:</u></em>
Thus speed of train is 25 meter per second