Answer: 1) 5040 and 2) 165
Step-by-step explanation:
1) Here total number of letters = 10
The number of permutations that can be formed using 4 letters at a time
= P (10, 4)
=
=
=
=
= 10 × 9 × 8 × 7
= 5040
2) Here the total number of machine = 11
The different combinations of machines can Geoff choose from to use
=
=
=
=
= 11 × 5 × 3
= 165