Question

George can do some work in 8 hours. paul can do the same work in 10 hours while hari can do the same work in 12 hours. all the three of them start working at 9 am. while george stops work at 11 am, the remaining two complete the work, approximately when will the work be finished?

Answer 1

work done in 2 hrs by 3 persons = 2*( 1/8+1/10+1/12) = 37/60 work. Balance 23/60 work is to be done by Paul and Hillari. Time taken by paul and hilari for 23/60 work = (23/60)*( 12*10/22)= 23/11 hrs so work will be completed by 13:05.27 hrs

Answer 2

Answer:

1 p.m.

Step-by-step explanation:

George can do some work in 8 hours.

George can do work in 1 hour = $\frac{1}{8}$

Paul can do the same work in 10 hours

Paul  can do work in 1 hour = $\frac{1}{10}$

Hari can do the same work in 12 hours

Hari can do work in 1 hour = $\frac{1}{12}$

They all can do work together in 1 hour =  $\frac{1}{8}+\frac{1}{10}+\frac{1}{12}$

                                                                   =  $\frac{37}{120}$

The three of them start working at 9 am. while george stops work at 11 am

They all can do work together in 2 hours =$\frac{37}{120} \times 2$

                                                                     =$\frac{37}{60}$  

Remaining work = $1- \frac{37}{60}$

                         = $\frac{23}{60}$

Paul  and Hari can do work in 1 hour = $\frac{1}{10}+\frac{1}{12}$

                                                             = $\frac{11}{60}$

So, Paul  and Hari can do  $\frac{11}{60}$  work in  hour =1

Paul  and Hari can do  whole work in  hour =$\frac{60}{11}$

Paul  and Hari can do $\frac{23}{60}$ work in  hour =$\frac{60}{11} \times \frac{23}{60}$

                                                                                                 =$\frac{23}{11}=2.09$

So, they will take approximately 2 hours to complete remining work after 11 a.m.

So, the work will be finished around 1 p.m.