10 thoughts on “FPC and PnC – CAT Scan 2

  1. i understood d logic but how can the total pairs be nc2 when it is given that the first no. will be less than the other one(i.e. i<j)…won't nc2 will include all the pairs of no., even when j is less than i…eg :(2,1)…

  2. Hi J,

    Thanks a ton for the article. 🙂 Apart from the concept , is there any shortcomings if we try to substitute the value of N here ? I tried to do it with n =4 and substituted the value of n in the options and got the correct answer . Wont substitution be a good option for these type of questions?

    • Yes KK it will be a valid approach 🙂 I went into the mathematical solution as I was focusing on the PnC-based approach! There are always many ways to solve any questions and options/substitution would definitely be one of your most powerful tools in a range of situations…


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