Just finished the test and the write answers are :
1) A,D,E
2)A,B
3)B,E
4) D
5) A
6) C
7) A
8) B
9) part A is C
Part B is A
Score 100%
Approximate solutions are
X subset 2 is approximately equal to -2.72
X subset 1 is approximately equal to -0.28
To answer this question we can propose the following equation:

Where:
x is the number of weeks elapsed.
d is the debt depending on the weeks.
Robert promised to pay at least $ 67 each week.
Therefore, after 5 weeks the debt of rober should be:


Then scenario A) is possible because
.
After 6 weeks:


Then scenario B) is possible because
.
After 7 weeks


Then scenario C) is possible because
.
After 8 weeks


So scenario D) is NOT possible because 
Finally the correct answer is option D.
Here we need the time, so
t = I/pr = (1336.6-820)/(820)(.045) = 14 years