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 work. Approximately at what time will the work (to print one lakh books) be finished ?

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Answers

2015-01-22T13:44:23+05:30

1 hour's work of P+Q+R = 1/8+1/10+1/12 = 37/120

Work done in 2 hrs by P,Q&R = 37/120*2 = 37/60

Remaining work = 1-37/60 = 23/60

1 hr's work of Q+R = 1/10+1/12 = 11/60

Work done by Q&R in 1 hr is 11/60

23/60 will be the work done by Q&R in 60/11*23/60 = 23/11 hrs≈2hrs

So approximately the work will be finished 2 hrs after 11A.M i.e around 1PM

 

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