# 2020 AMC 10A & AMC 12A Answer Key Released Posted by

Yesterday, thousands of middle school and high school students participated in this year’s AMC 10A and 12A Competition (including some students at Areteem Headquarters seen below).

The problems can now be discussed! See below for answer keys for both the 2020 AMC 10A and AMC 12A questions as well as the concepts tested on each problem.

1
E
algebra: linear equations with fractions
2
C
averages and means
3
A
algebra: factoring and simplifying linear fractions
4
E
algebra: motion and rates
5
C
algebra: quadratic equations and absolute values
6
B
combinatorics: counting digits and divisibility
7
C
magic squares, arithmetic sequences, and averages
8
B
sequences and patterns, arithmetic series
9
B
number theory: least common multiples
10
B
geometry: solid geometry and surface area of cubes
11
C
medians and arithmetic
12
C
geometry: triangles and medians, areas
13
B
combinatorics: total probability and symmetry
14
D
algebra: factoring and Vieta’s formulas
15
E
number theory: number of factors and square factors, probability
16
B
probability: geometric probability, cases
17
E
algebra: polynomials and graphs, patterns
18
C
combinatorics: cases and parity
19
E
combinatorics: geometric paths and logic
20
D
geometry: right triangles, similar triangles, and area
21
C
algebra: geometric sequences and factoring
22
A
number theory: floor function and factors
23
A
geometry: composing transformations
24
C
number theory: GCDs and remainders
25
A
combinatorics: probability and logic

1
C
fractions and percentages
2
C
geometry: distance formula and length
3
E
algebra: motion and rates
4
B
combinatorics: counting digits and divisibility
5
C
magic squares, arithmetic sequences, and averages
6
D
geometry: symmetry in a rectangle
7
B
geometry: solid geometry and surface area of cubes
8
C
medians and arithmetic
9
E
algebra: graphs of trigonometric functions
10
E
algebra: rules of logarithms
11
B
combinatorics: total probability and symmetry
12
B
geometry: coordinates and rotations
13
B
14
B
geometry: octagon and triangle areas
15
D
algebra: complex roots and polar form
16
B
probability: geometric probability, cases
17
D
algebra and geometry: logarithms and coordinate areas
18
D
geometry: right triangles, similar triangles, and area
19
C
algebra: geometric sequences and factoring
20
A
geometry: composing transformations
21
D
number theory: primes and factors
22
B
algebra: complex numbers and sequences
23
A
combinatorics: probability and logic
24
B
geometry: triangles and rotations
25
C
algebra: floor function and solving quadratic equations

In total 11 questions appeared on both the AMC 10A and AMC 12A. They are listed below:

 AMC 10A AMC 12A 4 3 6 4 7 5 10 7 11 8 13 11 16 16 20 18 21 19 23 20 25 23

Need to see all the problems and solutions? Areteem’s Dr. Kevin Wang has you covered, solving all 39 problems and giving problem solving tips in a review video. Click here for more information and to purchase. As a limited time offer, we’re giving the video out for free through social media. Check them out for instructions! The problems are available as a free download by clicking here.

The AMC 10 and 12 exams are administered by the Mathematical Association of America (MAA). For general information about the AMC 10 and 12, click here.