How many permutations exist of the letters a, b, c, d taken three at a time? a. 24 b. 12 c. 4

4P3 = 24

In a permutation order matters.

You can also think about it in this way; you have 3 spots to fill,

the first spot you have 4 items to choose from. Now there are only 3 items left to choose for the next spot. There are only 2 items left for the third spot, so

4 * 3 * 2 = 24

Letter A