Question

The Capital English alphabet has 11 symmetric letters that appear the same when looked at in a mirror. These letters are A, H, I, M, O, T, U, V, W, X, and Y. How many symmetric three letters passwords can be formed using these letters?

Answer 1

There are 11 symmetric letters.

∴ Number of 3 Letter passwords = ¹¹P₃

= 11 x 10 x 9

 = 990