If each shelf is to contain exactly 3 new CDs and there are only 5 shelves, only 15 can be placed in the rack. So, the answer to the second question is no. The same goes for the first question as placing 3 or fewer CDs to the shelves will make the rack insufficient for the CDs.
He would use 3 cages for the canaries (6 in each) and 6 cages for the parakeets (7 in each)
Can you define it much more simpler
Answer: 
Step-by-step explanation:
From the sports arena to Kristina's house = 
From the sports arena to Luke's house = 
Subtract Luke from Kristina

There's a confusing but easy way to solve this. However, I'm going to convert into improper fractions to make it easier.
To convert to improper fraction, take the whole number, multiply it by the denominator and add it to the numerator. All over the same denominator.


Subtract them.


Convert to mixed number by dividing.
65/10=6
60
----
5
The 6 is the whole number, 5 the numerator and 10 the denominator. Remember the negative sign that we had.

5 and 10 can be simplified
5/5=1
10/5=2
Our final answer would be:

I think C is a function since is passed the vertical line test.