If the 10 books are all different, we have:
• 10 ways of selecting the first book,
,
• 9 ways of selecting the second book,
,
• 8 ways of selecting the third book,
,
• 7 ways of selecting the fourth book.
The total number of ways to arrange 4 of the 10 books is:

Answer
There are 5040 ways of arranging the books.
Step-by-step explanation:
The answer is 130° since you subtract 4° from both sides
Answer:
20 and 25.
Step-by-step explanation:
Given:
They both teach total 45 yoga classes each week.
Erica teaches 15 fewer than twice as many as Bo.
To find:
How many classes does each instructor teach per week = ?
Solution:
Let number of classes are taken by Bo = 
Then number of classes are taken by Erica =
(given)
Total number of classes are taken by both = 45 (given)
According to the question.
+
= 45

By adding both side by 15

By dividing both side by 3

number of classes are taken by Bo =
= 20
number of classes are taken by Erica = 
= 
Therefore, number of classes are taken by Bo and Erica is 20 and 25.
Answer:
6 orders of the 10 burrito special
Step-by-step explanation:
10 burritos for $12
60 burritos for $72.
6 burritos for $7.50
10 burritos for $75
So the 10 burritos for $12 is better.
Hope this helps :D
Answer: D) 99 Points
Step-by-step explanation: Theresa earned scores of 88 points, 84 points, 88 points, and 91 points on four tests
Therefore the totals points are 351
351 is her total score for 4 tests, if she gets an average score of 90 on her fifth test then all we have to do is:
5 x 90 = 450 (The 5 being her fifth test)
450-351 = 99
Option D