A can complete a work in 12 days with a working of 8 hours per day. B can complete the
same work in 8 days when working 10 hours a day. If A and B work together, working 8 hours
a day, the work can be completed in
---days.
A. 5 5⁄11
B. 4 5⁄11
C. 6 4⁄11
D. 6 5⁄11

• P can complete the work in (12 x 8) hrs. = 96 hrs.
  
  Q can complete the work in (8 x 10) hrs. = 80 hrs.
  
  P's1 hour's work = 1/96 and Q's 1 hour's work = 1/80 .
  
  (P + Q)'s 1 hour's work = 1/96 + 1/80 = 11/480.
  
  So, both P and Q will finish the work in 480/11 hrs.
  
  Number of days of 8 hours each =(480/11) x (1/8) = 60/11 days.
  
  So, Ans is (A).
• 10 years agoHelpfull: Yes(28) No(0)
• p complete work in (12x8)= 96 hrs.
  p's 1 hrs work = 1/96
  q complete work in (8x10)= 80 hrs.
  q's 1 hrs work = 1/80
  then both finish work together in 8 hrs = 8(p + q)'s work
  8x1/96+8x1/80= 11/60
  so, 60/11 days.(A)
• 10 years agoHelpfull: Yes(1) No(0)
• A works for 12 days(8 hours per day)=96 hours
  B works for 8 days(10 hours per day)=80 hours
  Let the total work be 480 units
  A's 1 hour work=5 units-->A's 8 hour work=40 units
  B's 1 hour work=6 units-->B's 8 hour work=48 units
  Number of days=480/88=5 5/11
  option a) is correct
  
• 10 years agoHelpfull: Yes(0) No(0)
• 5 5/11 is the answer
• 10 years agoHelpfull: Yes(0) No(0)