In this task, you need to answer the given multiple-choice question on the physics. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.

[EX Q]: Problem: a train , 800 meter long is running with a speed of 78 km / hr . it crosses a tunnel in 1 minute . what is the length of the tunnel ? 
Options: a ) 650 meter , b ) 555 meter , c ) 500 meter , d ) 458 meter , e ) none of these
[EX A]: c

[EX Q]: Problem: a bullet train 200 m long is running with a speed of 69 kmph . in what time will it pass a man who is running at 3 kmph in the direction opposite to that in which the bullet train is going ? 
Options: a ) 10 sec , b ) 15 sec , c ) 12 sec , d ) 11 sec , e ) 16 sec
[EX A]: a

[EX Q]: Problem: 12 welders work at a constant rate they complete an order in 8 days . if after the first day , 9 welders start to work on the other project , how many more days the remaining welders will need to complete the rest of the order ? 
Options: a ) 5 , b ) 12 , c ) 18 , d ) 24 , e ) 28
[EX A]:
e