TASK DEFINITION: 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'.
PROBLEM: Problem: two trains of length 100 meters and 200 meters are 840 meters apart . they are moving towards each other on parallel tracks , at speeds of 54 km / h and 72 km / h . after how many seconds will the trains meet ? 
Options: a ) 20 , b ) 22 , c ) 24 , d ) 26 , e ) 28

SOLUTION: c

PROBLEM: Problem: two trains are running in opposite directions in the same speed . the length of each train is 120 meter . if they cross each other in 12 seconds , the speed of each train ( in km / hr ) is 
Options: a ) 30 km / hr , b ) 36 km / hr , c ) 80 km / hr , d ) 90 km / hr , e ) none of these

SOLUTION: b

PROBLEM: Problem: pipe a fills a swimming pool in 4 hours . pipe b empties the pool in 6 hours . if pipe a was opened at 9 : 00 am and pipe b at 10 : 00 am , at what time will the pool be full ? 
Options: a ) 19 : 00 , b ) 17 : 00 , c ) 16 : 00 , d ) 18 : 00 , e ) 20 : 00

SOLUTION:
a