Q. A does half as much work as B in three-fourth of the time. If together they take 18 days to complete the work, how much time shall B take to do it?.

• ans:
  
  let there are 18 works.
  together they take 18 days so per day they complete 1 work.
  so their efficiency per day is 1 work.
  
  now,
  let B completes the work in x days
  so efficiency of B per day is 18/x works.
  
  as per question B will complete half of the work in 3/4 times x
  i.e; A will complete 0.5*(18) works in 3x/4 time
  so A will complete 9 works in 3x/4 time
  now the amount of work done by A in x time is (9)*(4/3) = 12 works
  
  so efficiency of A per day is 12/x
  
  together their efficiency per day is 1 work
  so we can write 18/x + 12/x =1
  30/x = 1
  x=30
  we get time taken by B to complete the work to be 30 days.
  
  hope you like my solution. pls give feed back
• 11 years agoHelpfull: Yes(4) No(1)
• efficiency of A:B=2:3
  time taken to complete the work =18 hrs
  so if capability of both dng the wrk is 2+3=5,5 wrk in an hour...........total work will be=18*5 i.e 90
  A time taken to do the work alone is (90/2=45 days)
  abd B takes time to do the work alone is (90/3=30 days)
• 10 years agoHelpfull: Yes(3) No(1)
• mr ankit kedia your 2nd line is wrong according to question because A will complete the half of work in (3/4)x time k.
• 11 years agoHelpfull: Yes(1) No(0)
• Let B take x days to complete the work
  SO A will complete the work in (3/4)x days
  now A's one day work = 1/x
  B's one day work = 4/3 x
  A + B 's one day work = 1/x + 4/3x
  = 7/3x
  therefore 7/3x = 1/18
  using simple calculation x = 18 * 7 / 3
  = 42
  So B will complete the work in 42 days
• 11 years agoHelpfull: Yes(0) No(3)