Each of the 11 letters A, H, I, M, O, T, U, V, W, X and Z appears same when looked at in a mirror. They are called symmetric letters. Other letters in the alphabet are asymmetric letters. How many four letter computer passwords can be formed (no repetition allowed) with at least one symmetric letter	Choose the correct choice from the following answers.
A) 2,145
B) 6,435
C) 12,100
D) 12,870
E) 326,040
Since we are given atleast one symmetric letter in the three letter word we can take the following cases   1. All four   2. One symmetry and other three non   3. Two symmetry and other two non   4. Three symmetry and one non   4. All the three letters can be arranged in 24 ways   ( 11c4 + 11c1 * 15c3 + 11c2 * 15c2 + 11c3 *15c1 ) * 6   (330 +5005 + 5775+2475 ) * 24   326,040   IMO option E is the correct answer..   OA please...will correct if I missed anything.. 326,040
<result>E</result>
Each of the 11 letters A, H, I, M, O, T, U, V, W, X and Z appears same when looked at in a mirror. They are called symmetric letters. Other letters in the alphabet are asymmetric letters. How many four letter computer passwords can be formed (no repetition allowed) with at least one symmetric letter