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
Answered by Mimiwhatsup: (5 - 10) 4
The parenthesis indicate anything on the outside that doesn't have a plus or minus or division symbol indicates to multiply.
Answer:
all work is shown and pictured