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 a and b are 125 m and 150 m long and are moving at one another at 54 km / hr and 36 km / hr respectively . arun is sitting on coach b 1 of train a . calculate the time taken by arun to completely cross train b . 
Options: a ) 10 s , b ) 11 s , c ) 4 s , d ) 8 s , e ) 12 s

SOLUTION: b

PROBLEM: Problem: if the product of two numbers is 45276 and their h . c . f . is 22 , find their l . c . m . 
Options: a ) 2574 , b ) 2500 , c ) 2100 , d ) 2058 , e ) none of these

SOLUTION: d

PROBLEM: Problem: pumps a , b , and c operate at their respective constant rates . pumps a and b , operating simultaneously , can fill a certain tank in 6 / 5 hours ; pumps a and c , operating simultaneously , can fill the tank in 3 / 2 hours ; and pumps b and c , operating simultaneously , can fill the tank in 1 hours . how many hours does it take pumps a , b , and c , operating simultaneously , to fill the tank . 
Options: a ) 37 / 20 , b ) 1 / 2 , c ) 1 / 4 , d ) 1 , e ) 5 / 6

SOLUTION:
a