two good train each 750 m long, are running in opposite directions on parallel tracks. their speeds are 45 km / hr and 30 km / hr respectively. find the time taken by the slower train to pass the driver of the faster one.  Choose the correct choice from the following: A) 12 sec B) 24 sec C) 48 sec D) 72 sec E) none
<gadget id="calculator">45 + 30</gadget>
<output>75</output>

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

<gadget id="calculator">75 * (5/18)</gadget>
<output>125/6 = around 20.833333</output>

<gadget id="calculator">1 / (125/6)</gadget>
<output>6/125 = around 0.048</output>

<gadget id="calculator">750 * (6/125)</gadget>
<output>36</output>

<gadget id="calculator">36 * 2</gadget>
<output>72</output>

<result>D</result>
two good train each 750 m long, are running in opposite directions on parallel tracks. their speeds are 45 km / hr and 30 km / hr respectively. find the time taken by the slower train to pass the driver of the faster one.
multiply(multiply(750, inverse(multiply(add(45, 30), const_0_2778))), const_2)
"sol . relative speed = ( 45 + 30 ) km / hr = ( 75 x 5 / 18 ) m / sec = ( 125 / 6 ) m / sec . distance covered = ( 750 + 750 ) m = 1500 m . required time = ( 1500 x 6 / 125 ) sec = 72 sec . answer d"