Two workers A and B are engaged to do a piece of work. Working alone, A takes 8 hours more to complete the work than if both worked together. On the other hand, working alone, B would need 2 4 1 hours more to complete
the work than if both worked together. How much time would they take to complete the job working together?
option
(A) 4 Hours
(B) 5 Hours
(C) 6 Hours
(D) 7 Hours

• Let X be the hours taken to complete work by Both A & B.
  
  Then time taken by A is (X + 8) Hours
  Similarly time taken by B is (X+9/2) Hours
  
  We know that
  
  1/(X+8) + 1/(X+9/2) = 1/X
  (X+9/2)+(X+8) = (X+8)(X+9/2)/X
  
  Solve the Equation you get
  X = 6 Hours
  
• 8 years agoHelpfull: Yes(1) No(0)