Grace is travelling to Italy with her family.
She has bought a puzzle book to keep herself entertained on the aeroplane.
One of the questions in the book is:
How many different ways are there to arrange the letters A, B, C, D, E, F when each letter must be used exactly once?
Help Grace find the answer.
Answer:
To place the first letter, you could pick any of the 6 letters.
For the next one there are only 5 to choose from since one has already been used.
The third letter has only 4 options since 2 have already been placed, and so on..
6! = 6 x 5 x 4 x 3 x 2 x 1 = 720 combinations