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 man started driving at a constant speed , from the site of a blast , the moment he heard the blast . he heard a second blast after a time of 30 mins and 12 seconds . if the second blast occurred exactly 30 mins after the first , how many meters was he from the site when he heard the second blast ? ( speed of sound = 330 m / s )
Options: a ) 3120 , b ) 3330 , c ) 3540 , d ) 3750 , e ) 3960
[EX A]: e

[EX Q]: Problem: a train 300 m long takes 9 sec to cross a man walking at 3 kmph in a direction opposite to that of the train . find the speed of the train ?
Options: a ) 100 kmph , b ) 90 kmph , c ) 120 kmph , d ) 117 kmph , e ) 125 kmph
[EX A]: d

[EX Q]: Problem: you have a flashlight that takes 2 working batteries . you have 8 batteries but only 4 of them work . what is the fewest number of pairs you need to test to guarantee you can get the flashlight on ?
Options: a ) 5 , b ) 8 , c ) 7 , d ) 6 , e ) 4
[EX A]:
c