a 250 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. what is the length of the other train?  Select:	A) 230 m	B) 240 m	C) 250 m	D) 260 m	E) 270 m
<gadget id="calculator">120 + 80</gadget>
<output>200</output>

<gadget id="calculator">10 / 36</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">200 * (5/18)</gadget>
<output>500/9 = around 55.555556</output>

<gadget id="calculator">(500/9) * 9</gadget>
<output>500</output>

<gadget id="calculator">500 - 250</gadget>
<output>250</output>

<result>C</result>
a 250 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. what is the length of the other train?
subtract(multiply(multiply(add(120, 80), const_0_2778), 9), 250)
"speed = ( 120 + 80 ) km / h ( because direction is opposite hence relative velocity is added ) = 500 / 9 m / s time = 9 sec let the lenght of second train is x total distance covered = 250 + x therefore , d = speed * time thus 250 + x = 500 / 9 * 9 x = 500 - 250 = 250 m answer : c"