Answer:

Step-by-step explanation:
First, find the probability of him pulling out a book.
There are 11 objects in total, and there are 4 books.
So, the probability of pulling out a book is 
Next, find the probability of him pulling out a DVD after.
Since a book was taken out, there are only 10 objects left. There are 5 DVDs.
So, the probability of pulling out a DVD is
, or simplified to 
To find the probability that this happens in order, multiply the probabilities:
x 
= 
So, the probability is 
Answer:
Step-by-step explanation:first:4+8 then 12*2 after:24+4
(7+x)+x=15
I did trial and error to get x=4.
Answer:
2 x 2 x 7, or 2^2 x 7
Step-by-step explanation:
Let us use prime factorization to find the prime numbers that make up 28:
28 = 2 x 14
2 is a prime number, 14 is not, so we have our first prime, 2.
14 = 2 x 7
We then further break the number down into two prime numbers, 2 and 7. Since 2 and 7 are prime and we can't break them down any further our answer is 2 x 2 x 7, or 2^2 x 7.
The answer is 22 :) I hope that helped