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
The decimal is about 1.1 and you can’t simplify it
The inverse of -2.5 is 2.5 ;]
<span>46 <= grade < 96
First, let's write the equation for the lower limit that the student must get for a B.
(x + 92 + 82 + 88 + 92)/5 = 80
Multiply both sides by 5 giving
x + 92 + 82 + 88 + 92 = 400
Subtract 92, 82, 88, 92 from both sides
x = 400 - 92 - 82 - 88 - 92 = 46
So the student has to get 46 or higher on the test to make a B.
Now let's compute the upper limit
(x + 92 + 82 + 88 + 92)/5 < 90
Multiply both sides by 5
(x + 92 + 82 + 88 + 92) < 450
Subtract 92, 82, 88, 92 from both sides
x < 450 - 92 - 82 - 88 - 92 ) = 96
So the student has to get a grade of less than 96 to get a B.</span>