Hi,gmat1978 wrote:I got it wrong. A,B,C,D are 4 letters and P,Q,R,S are corresponding envelopes. Let's put A in the correct envelope(P). We can do that only in 1 way right? Can you please point out the flaw in my thought process?cans wrote: No. of ways of selecting that particular letter = 4C1 = 4.
Suppose we select D.
Thanks
Yes.. If you pick A, you will put it in correct envelope in 1 way. Similar in another case, you will B and put in correct envelope Q. Similarly for the other 2 letters. So, By adding all these, it gives you 4 ways.
