1)
How many permutations of the letters a, b, c, d, e, f, g have either two or three letters between a and b?
11@Vivek, when it is not mention about the way of taking the digits we have to ignore those ways where there is repetion of digits.
Read this lesson for more info.
11Even if the words are of 6 letters or 7 letters there can be cases where there can be letters between a and b. Hope my solution makes this clear to you.
See in my post my #9 where I have written this a and b can also be arranged among themselves in 2 ways, so
The 2 which I have written inside the bracket is for the arrangements of a and b, so there is no need to take them separately.
71See in my post my #9 where I have written this a and b can also be arranged among themselves in 2 ways, so
I too have taken that case.
when it is not mention about the way of taking the digits we have to ignore those ways where there is repetion of digits.
Where is the repeatation being made?
Still I think that we don't have to form 4 letter or 5 letter or 6 letter word. Only a single 7 letter word in all possible ways! (I mean corresponding to given conditions).
I have seen such problems I think.
Say letter ABCDF are given and we are to form such that there is one space between A & C. I don't think you'll form a 3 letter word or such.
71Point out mistakes in my concept/solution of my #Post11 dear!
11And y you think that u have to make only 7 lettered words?, other conditions are very much possible.
