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: pipes a and b can fill a tank in 3 and 4 hours . pipe c can empty it in 4 hours . if all pipes are opened together , then the tank will be filled in ? 
Options: a ) 3 hr , b ) 1 / 2 hr , c ) 1 hr , d ) 9 / 7 hr , e ) 5 / 3 hr
[EX A]: a

[EX Q]: Problem: ram , who is half as efficient as krish , will take 24 days to complete a task if he worked alone . if ram and krish worked together , how long will they take to complete the task ? 
Options: a ) 16 days , b ) 12 days , c ) 8 days , d ) 6 days , e ) 18 days
[EX A]: c

[EX Q]: Problem: a can give b 60 meters start and c 120 meters start in a kilometer race . how much start can b give c in a kilometer race ? 
Options: a ) 63.83 , b ) 111.67 , c ) 111.64 , d ) 111.11 , e ) 101.12
[EX A]:
a