A wall clock gains 2 mins in 12 hrs, while a table clock

This problem tests the concept of relative rates

We have that a wall clack gains 2 min every 12 hours
Another one loses two minutes every 36 hours

First we need to get the rates to be equivalent so multiplying the first by three we get 6 min every 36 hours

Now, if they move 8 min apart in 36 hours, how much will it take them to show the same time. Well one has to imagine that one of the needles is fixed and the other will move 8 min every 36 hours until it makes a whole turn and reaches the same point. That is the basic concept of relative rates. To do so, since it is a wall clock, we will need it to turn a distance equivalent to 12 hours. Now 12*60 = 720 minutes.

So by direct proportionality we get 720*36/8 that is the time it will take in minutes, divide by 60 to get the time in hours. One will get 54 hours

Now since its 54 hours therefore, it will show exactly the same time cause we have no remainder.

So B is our best answer here

Is this clear?

Hope it helps
Cheers!
J