Machine P can print one lack books in 8 hours. Machine Q can print the same number of
books in 10 hours while machine R can print the same in 12 hours. All the machines started
printing at 9 A.M. Machine P is stopped at 11 A.M. and the remaining two machines complete
work. Approximately at what time will the printing of one lack books be completed?
A. 3 pm
B. 2 pm
C. 1:00 pm
D. 11am

• (P + Q + R)'s 1 hour's work =(1/8 + 1/10 + 1/12)= 37/120
  Work done by P, Q and R in 2 hours=(2*37/120)= 37/60
  
  Remaining work = (1- 37/60) = 23/60
  
  (Q + R)'s 1 hour's work =(1/10 + 1/12)=11/60
  so now, 11/60 work is done by Q and R in 1 hour
  so 23/60 work will be done by Q and R in(60/11*23/60)= 23/11 hours = approx 2hrs
  so, the work will be finished approximately 2 hours after 11 A.M.
  i.e., around 1:00 pm
• 10 years agoHelpfull: Yes(22) No(0)
• efficiency of P= 1/8
  efficiency of Q= 1/10
  efficiency of R= 1/12
  P works for 2 hours and let time taken Q and R be x
  so we can write
  2(1/8)+x(1/10)+x(1/12)= 1 (total work done)
  now solve for x
  ans(approx)= 1:00pm
  
• 10 years agoHelpfull: Yes(2) No(0)
• ans is 1 .09 pm . and approximately its 1:00 pm.
• 9 years agoHelpfull: Yes(2) No(0)
• P can print 1 lack books in 8 hours
  so it can print 25,000 books in 2 hours
  Q can print 10,000 books in 1 hour
  R can print 8333 books in 1 hour
  
  so after 2 hours of work = 25000+20000+16666= 61666
  so books remain 38334
  so together they can print 18333 books in 1 hour
  so in 2 hours they will print 36666 books.
  and in the next hour they will complete the work.
  11AM + 2 hours + 1 hour = 2 PM
  B is the correct answer.
• 10 years agoHelpfull: Yes(0) No(5)
• At 1.00pm work will be completed
• 9 years agoHelpfull: Yes(0) No(0)