Please help me out with a few multiple choice questions? please??

Question

Question #1
Chris stopped for gas twice on a long car trip.The price of gas at the first station was $1.45 per gallon, and the price of gas at the second station was $1.55 per gallon. On the trip, Chris bought a total of 20 gallons of gas and spent $29.80. Let x= the number of gallons that Chris bought at the first station and y = the number of gallons Chris bought at the second station.

Solve the system of equations to find the number of gallons that Chris bought at the second station.

A.) 5
B.) 8
C.) 12
D.) 20

Question #2
Look at the question below and determine the appropriate skill level.

Based on what you learned in the essay,construct a table to show the main ideas.

A.) Knowledge
B.) Application
C.) Synthesis
D.) Evaluation

Question #3
Look at the question below and determine the appropriate skill level.

Compare and contrast the main characters of the two short stories.

A.) Knowledge
B.) Comprehension
C.) Analysis
D.)Evaluation

Please help!

Answer 1

1.b
2.D
3.B

Answer 2

Let x= the number of gallons that Chris bought at the first station and y = the number of gallons Chris bought at the second station.

I use cents, rather than dollars to simplify.
145x + 155y = 2980
x + y = 20
x = 20-y
145(20-y) +155y = 2980
2900 -145y +155y = 2980
10y = 80
y = 8, x = 12
Answer B

Answer 3

First answer is B.

I don't get the other 2.