Question

determine whether the following problem involves a permutation or combination. (it is not necessary to solve the problem.)
how many different 2-letter passwords can be formed from the letters a, b, c, d, e, f, and g if no repetition of letters is allowed?
problem involves a ____ because the __ of letters selected ____ matter.

Explanation:

Permutations are used when the order of selected items matters, while combinations are used when order does not matter. For passwords, a sequence like "AB" is a different password than "BA", so the order of the letters directly changes the result.

Answer:

problem involves a permutation because the order of letters selected does matter.