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There are 11 alphabets A, H, I, M, O, T, U, V, W, X, Y, Z. They are called symmetrical alphabets. The remaining alphabets are known as asymmetrical alphabets.

How many four-lettered passwords can be formed by using symmetrical letters only? (repetitions not allowed)

  1. $1086$
  2. $255$
  3. $7920$
  4. None of these
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These are 12 letters

No repetition is allowed so possible number of passwords of four letters 

12 11 10 9

=12*11*10*9

=11880 

If There are 11 letters

No repetition is allowed so possible number of passwords of four letters 

11 10 9 8

=11*10*9*8

=7920 

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