Four cards labeled A, B, C, and D are randomly placed in four boxes labeled A, B, C, and D. Each box receives exactly one card.

In how many ways can the cards be placed in the boxes?

24 ways.

Step-by-step explanation:

You can put any of the first cards in box A, you can do this in 4 different ways. For the second card, you'll have 3 options to put it in box B. For the third card, you'll have 2 options to put it in box C. For the last card, you'll only have 1 option (the remaining card will have to go to box D).

Therefore you have 4 x 3 x 2 x 1 = 24 ways of place the cards in the boxes.