Help 10 ​

Here is me trying:

There are 6 letters, right? All of them are different. You make a tree diagram or a chart.

There are this many: FA, FB, FR, FI, FC, AF, AB, AR, AI, AC, BF, BA, BR, BI, BC, RF, RA, RB, RI, RC, IF, IA, IB, IR, IC, CF, CA, CB, CR, CI.

That is if the same letter cannot be used twice within one permutation. If that can happen, then add 6 to the number.

My answer: 30

P(6,2)  = 30

Good Job, Tanmai......!!!!!