Question

How many different 2-letter passwords can be formed from the letters O, P, Q, R, S, T, and U if no repetition of letters is allowed?
The problem involves a__
because the__
of letters selected
___matter

Answer 1

Answer:

Below.

Step-by-step-explanation:

This is the number of permutations of 2 from 7.

= 7! / (7-2)!

= 7*6*5*4*3*2*1 / 5*4*3*2*1

= 7 * 6

= 42.

Its a permutation because the order of letters do matter,.