I’ve deliberately avoided going into too much detail (spoonfeeding); I believe you should be able to figure it out with the hints and info provided 🙂 That’s the only way you will be able to apply it for yourself in future. So no, I’m afraid I won’t give more detail.
“First black second white” is different from “First white second black” but “First black second black” is the same as “First black second black”…in a way it is the basic difference between permutation and combination.
CAT-holics 
sir
can you pls explain 2nd ques in detail? i am not able to understand with the given solution..
I’ve deliberately avoided going into too much detail (spoonfeeding); I believe you should be able to figure it out with the hints and info provided 🙂 That’s the only way you will be able to apply it for yourself in future. So no, I’m afraid I won’t give more detail.
regards
J
Hi J,
Why is it that the order matters in the black and white question (768 ans) but doesn’t in the two blacks (400 ans) question?
“First black second white” is different from “First white second black” but “First black second black” is the same as “First black second black”…in a way it is the basic difference between permutation and combination.
regards
J
Hi Sir, should one solve all past CAT papers from 2000-2019? or is it okay to start from 2016?
You will not find genuine papers from 2009-2016. So solve 2017-2019 for sure, and at least some from 2002-2008 if you can.
regards
J