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: a can do a work in 8 days . b can do the same work in 16 days . if both a & b are working together in how many days they will finish the work ? 
Options: a ) 3 days , b ) 16 / 3 days , c ) 3 / 4 days , d ) 9 / 12 days , e ) 5 / 7 days
b

Problem: a company produces 72000 bottles of water everyday . if a case can hold 10 bottles of water . how many cases are required by the company to hold its one day production 
Options: a ) 2000 , b ) 4500 , c ) 5000 , d ) 7200 , e ) 9000
d

Problem: the sum of the squares of three consecutive natural number is 2030 . what is the middle number ? 
Options: a ) 25 , b ) 26 , c ) 27 , d ) 28 , e ) 29

b