Total money Marcus has = $28
Money spent to buy a notebook = $3.75
Money left now = 
Money needed to be saved = $11.25
So, the amount of money Marcus can spend = 
Cost of a packet of chips = $1.30
The inequality to determine the maximum number of chips he can buy is:
Let the number of chips Marcus can buy = x
As he cannot spend more than $13 to buy chips so equation becomes:

Solving this we get

Hence, Marcus can buy a maximum of 10 packs of chips and save $11.25
1) Gathering the data
P=$6200
F=7310
t= 3 yrs
2) Since it is a simple interest, it is a linear application. So we can find it using this formula:
Answer:
1.46
Step-by-step explanation:
First find the the mean score before he made a 90.

Now add the score of 90 and calculate.

Subtract the two scores.

His mean test score increased by 1.46.
Check picture below, solve for "x" and "y"
unless you've already covered the 30-60-90 triangle, then check your book on them, to see the ratios, using the 30-60-90 ratios is simpler
1) No. 28/21 does not end up being equal to 2.
2) No. 45/5 does not equal 18/2
3) No. For something to be proportional, it should at least have the smaller number in the same place.
4) No. 25/12 does not equal 53/40
5) Yes. 4/2 is equal to 14/7
6) Yes. 4/1 is equla to 12/3
7) No. For something to be proportional, it should at least have the smaller number in the same place.
8) No. 44/9 is not equal to 36/11
9) Yes. 10/5 is equal to 16/8
10) Yes. 24/12 is equal to 14/7
11) No. 24/4 is not equal to 42/9
12) Yes. Both equal 1.
13) Yes. 20/5 is equal to 44/11
14) No. 44/40 is not equal to 34/30
15) Yes . 40/4 is equal to 10/1
16) Yes. 36/4 is equal to 45/5
17) No. 16/2 is not equal to 13/1
18) No. 38/9 is not equal to 28/7
19) Yes. This is a common proportion.
20) Yes. 50/25 is equal to 2.
21) Yes. 36/24 is equal to 3/2.
22) Yes. 18/12 is equal to 42/28
23) No. 33/42 is not equal to 27/37
24) No. 34/7 is not 4
25) Yes. The second proportion listed is half of the first
26) Yes. This is proportional.
27) Yes. This is proportional.
28) Yes. This is proportional.
29) No. This is not proportional.
30) No. This is not proportional
31) Yes. This is proportional.
32) Yes. This is proportional
33)
34)
35)
36)
37)
38)
39)
40)
I hope this helped. I left the last few unsolved so you could follow the patterns to find them out!