Question

10 th question . Please answer fast

Answer 1

Answer:

Option(D)

Step-by-step explanation:

10.

Work done by P in 1 hour = 1/8 .

Work done by Q in 1 hour = 1/10 .

Work done by R in 1 hour = 1/12 .

Now,

Work done by P,Q and R in 1 hour = 1/8 + 1/10 + 1/12

                                                        = 37/120

Work done by Q and R in 1 hour = 1/10 + 1/12

                                                      = 11/60

From 9 am to 11 am, all the machines were operating.

They all operated for 2 hours and work completed :

= 2 * (37/120)

= 37/60

Remaining work = 1- 37/60

                           = 23/60

So,

23/11 work will be done by Q and R in,

= (23/60) * (60/11)

= 23/11

= ~2 hours

Hence the work will be completed approximately 2 hours after 11 am,

= 1 PM

Therefore,

Work will be finished at 1 PM

Hope it helps!