A machine P can print one lakh books in 8 hours, machine Q can print the same number of books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 a.m. while machine P is closed at 11 a.m. and the remaining two machines complete the work. Approximately at what time will the work be finished?	Choose the correct choice from the following choices:	A) 11 : 30 am	B) 12 noon	C) 12 : 30 pm	D) 1 pm	E) None of these
(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 = (37⁄120 × 2) = 37⁄60   Remaining work = (1 - 37⁄60) = 23⁄60   (Q + R)’s 1 hour’s work = (1⁄10 + 1⁄12) = 11⁄60   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 ≈ 2 hours.   So, the work will be finished approximately 2 hours after 11 a.m., i.e., around 1 p.m.   Answer 1 pm
<result>D</result>
A machine P can print one lakh books in 8 hours, machine Q can print the same number of books in 10 hours while machine R can print them in 12 hours. All the machines are started at 9 a.m. while machine P is closed at 11 a.m. and the remaining two machines complete the work. Approximately at what time will the work be finished?