Exam Complete | AMC 10B 2020
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Topic Breakdown

Number Theory Weak 0/9 · 0%
Geometry Weak 0/7 · 0%
Counting and Probability Weak 0/7 · 0%
Algebra Weak 0/2 · 0%

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Results by Question

1 Algebra
Wrong
What is the value of \( 1 - ( - 2 ) - 3 - ( - 4 ) - 5 - ( - 6 ) ? \)
A
\(- 20\)
B
\(- 3\)
C
\(3\)
\(5\)
Correct Answer
E
\(21\)
No explanation
2 Geometry
Wrong
Carl has \(5\) cubes each having side length \(1\), and Kate has \(5\) cubes each having side length \(2\). What is the total volume of these \(10\) cubes?
A
\(24\)
B
\(25\)
C
\(28\)
D
\(40\)
\(45\)
Correct Answer
No explanation
3 Algebra
Wrong
The ratio of \(w\) to \(x\) is \(4 : 3\), the ratio of \(y\) to \(z\) is \(3 : 2\), and the ratio of \(z\) to \(x\) is \(1 : 6\). What is the ratio of \(w\) to \(y ?\)
A
\(4 : 3\)
B
\(3 : 2\)
C
\(8 : 3\)
D
\(4 : 1\)
\(16 : 3\)
Correct Answer
No explanation
4 Number Theory
Wrong
The acute angles of a right triangle are \(a^\circ\) and \(b^\circ\), where \(a > b\) and both \(a\) and \(b\) are prime numbers. What is the least possible value of \(b\)?
A
\(2\)
B
\(3\)
C
\(5\)
\(7\)
Correct Answer
E
\(11\)
No explanation
5 Counting and Probability
Wrong
How many distinguishable arrangements are there of \(1\) brown tile, \(1\) purple tile, \(2\) green tiles, and \(3\) yellow tiles in a row from left to right? (Tiles of the same color are indistinguishable.)
A
\(210\)
\(420\)
Correct Answer
C
\(630\)
D
\(840\)
E
\(1050\)
No explanation
6 Number Theory
Wrong
Driving along a highway, Megan noticed that her odometer showed \(15951\) (miles). This number is a palindrome-it reads the same forward and backward. Then \(2\) hours later, the odometer displayed the next higher palindrome. What was her average speed, in miles per hour, during this \(2\)-hour period?
A
\(50\)
\(55\)
Correct Answer
C
\(60\)
D
\(65\)
E
\(70\)
No explanation
7 Number Theory
Wrong
How many positive even multiples of \(3\) less than \(2020\) are perfect squares?
\(7\)
Correct Answer
B
\(8\)
C
\(9\)
D
\(10\)
E
\(12\)
No explanation
8 Geometry
Wrong
Points \(P\) and \(Q\) lie in a plane with \(P Q = 8\). How many locations for point \(R\) in this plane are there such that the triangle with vertices \(P\), \(Q\), and \(R\) is a right triangle with area \(12\) square units?
A
\(2\)
B
\(4\)
C
\(6\)
\(8\)
Correct Answer
E
\(12\)
No explanation
9 Number Theory
Wrong
How many ordered pairs of integers \(( x , y )\) satisfy the equation \( x^2020 + y^2 = 2 y ? \)
A
\(1\)
B
\(2\)
C
\(3\)
\(4\)
Correct Answer
E
\(\text{infinitely many}\)
No explanation
10 Geometry
Wrong
A three-quarter sector of a circle of radius \(4\) inches together with its interior can be rolled up to form the lateral surface area of a right circular cone by taping together along the two radii shown. What is the volume of the cone in cubic inches?
A
\(3 \pi \sqrt{5}\)
B
\(4 \pi \sqrt{3}\)
\(3 \pi \sqrt{7}\)
Correct Answer
D
\(6 \pi \sqrt{3}\)
E
\(6 \pi \sqrt{7}\)
No explanation
11 Counting and Probability
Wrong
Ms.~Carr asks her students to read any \(5\) of the \(10\) books on a reading list. Harold randomly selects \(5\) books from this list, and Betty does the same. What is the probability that there are exactly \(2\) books that they both select?
A
\(\dfrac{1}{8}\)
B
\(\dfrac{5}{36}\)
C
\(\dfrac{14}{45}\)
\(\dfrac{25}{63}\)
Correct Answer
E
\(\dfrac{1}{2}\)
No explanation
12 Number Theory
Wrong
The decimal representation of \( \dfrac{1}{2}0^20 \) consists of a string of zeros after the decimal point, followed by a \(9\) and then several more digits. How many zeros are in that initial string of zeros after the decimal point?
A
\(23\)
B
\(24\)
C
\(25\)
\(26\)
Correct Answer
E
\(27\)
No explanation
13 Geometry
Wrong
Andy the Ant lives on a coordinate plane and is currently at \(( - 20 , 20 )\) facing east (that is, in the positive \(x\)-direction). Andy moves \(1\) unit and then turns \(90^\circ\) left. From there, Andy moves \(2\) units (north) and then turns \(90^\circ\) left. He then moves \(3\) units (west) and again turns \(90^\circ\) left. Andy continues his progress, increasing his distance each time by \(1\) unit and always turning left. What is the location of the point which Andy makes the \(2020\) left turn? \(\mathbf{\text{(E)}} ( - 1022 , - 994 )\)
A
\(( - 1030 , - 994 )\)
\(( - 1030 , - 990 )\)
Correct Answer
C
\(( - 1026 , - 994 )\)
D
\(( - 1026 , - 990 )\)
No explanation
14 Geometry
Wrong
As shown in the figure below, six semicircles lie in the interior of a regular hexagon with side length 2 so that the diameters of the semicircles coincide with the sides of the hexagon. What is the area of the shaded region --- inside the hexagon but outside all of the semicircles?
A
\(6 \sqrt{3} - 3 \pi\)
B
\(\dfrac{9 \sqrt{3}}{2} - 2 \pi\)
C
\(\dfrac{3 \sqrt{3}}{2} - \dfrac{\pi}{3}\)
\(3 \sqrt{3} - \pi\)
Correct Answer
E
\(\dfrac{9 \sqrt{3}}{2} - \pi\)
No explanation
15 Number Theory
Wrong
Steve wrote the digits \(1\), \(2\), \(3\), \(4\), and \(5\) in order repeatedly from left to right, forming a list of \(10 , 000\) digits, beginning \(123451234512 \cdots .\) He then erased every third digit from his list (that is, the \(3\)rd, \(6\)th, \(9\)th, \(\cdots\) digits from the left), then erased every fourth digit from the resulting list (that is, the \(4\)th, \(8\)th, \(12\)th, \(\cdots\) digits from the left in what remained), and then erased every fifth digit from what remained at that point. What is the sum of the three digits that were then in the positions \(2019 , 2020 , 2021\)?
A
\(7\)
B
\(9\)
C
\(10\)
\(11\)
Correct Answer
E
\(12\)
No explanation
16 Counting and Probability
Wrong
Bela and Jenn play the following game on the closed interval \([ 0 , n ]\) of the real number line, where \(n\) is a fixed integer greater than \(4\). They take turns playing, with Bela going first. At his first turn, Bela chooses any real number in the interval \([ 0 , n ]\). Thereafter, the player whose turn it is chooses a real number that is more than one unit away from all numbers previously chosen by either player. A player unable to choose such a number loses. Using optimal strategy, which player will win the game? \(\mathbf{\text{(D)}} \text{ Jenn will win if and only if } n \text{ is odd.} #h(2em) \mathbf{\text{(E)}} \text{ Jenn will win if and only if } n > 8 .\)
\(\text{ Bela will always win.}\)
Correct Answer
B
\(\text{ Jenn will always win.}\)
C
\(\text{ Bela will win if and only if } n \text{ is odd.}\)
No explanation
17 Counting and Probability
Wrong
There are \(10\) people standing equally spaced around a circle. Each person knows exactly \(3\) of the other \(9\) people: the \(2\) people standing next to him or her, as well as the person directly across the circle. How many ways are there for the \(10\) people to split up into \(5\) pairs so that the members of each pair know each other?
A
\(11\)
B
\(12\)
\(13\)
Correct Answer
D
\(14\)
E
\(15\)
No explanation
18 Counting and Probability
Wrong
An urn contains one red ball and one blue ball. A box of extra red and blue balls lies nearby. George performs the following operation four times: he draws a ball from the urn at random and then takes a ball of the same color from the box and returns those two matching balls to the urn. After the four iterations the urn contains six balls. What is the probability that the urn contains three balls of each color?
A
\(\dfrac{1}{6}\)
\(\dfrac{1}{5}\)
Correct Answer
C
\(\dfrac{1}{4}\)
D
\(\dfrac{1}{3}\)
E
\(\dfrac{1}{2}\)
No explanation
19 Counting and Probability
Wrong
In a certain card game, a player is dealt a hand of \(10\) cards from a deck of \(52\) distinct cards. The number of distinct (unordered) hands that can be dealt to the player can be written as \(158 A 00 A 4 A A 0\). What is the digit \(A\)?
\(2\)
Correct Answer
B
\(3\)
C
\(4\)
D
\(6\)
E
\(7\)
No explanation
20 Geometry
Wrong
Let \(B\) be a right rectangular prism (box) with edges lengths \$1,\$3, and \(4\), together with its interior. For real \(r \geq 0\), let \(S ( r )\) be the set of points in \(3\)-dimensional space that lie within a distance \(r\) of some point in \(B\). The volume of \(S ( r )\) can be expressed as \(a r^3 + b r^2 + c r + d\), where \(a , \) b , \( c ,\) and \(d\) are positive real numbers. What is \(\dfrac{b c}{a d} ?\)
A
\(6\)
\(19\)
Correct Answer
C
\(24\)
D
\(26\)
E
\(38\)
No explanation
21 Geometry
Wrong
In square \(A B C D\), points \(E\) and \(H\) lie on \(\overline{A B}\) and \(\overline{D A}\), respectively, so that \(A E = A H .\) Points \(F\) and \(G\) lie on \(\overline{B C}\) and \(\overline{C D}\), respectively, and points \(I\) and \(J\) lie on \(\overline{E H}\) so that \(\overline{F I} \perp \overline{E H}\) and \(\overline{G J} \perp \overline{E H}\). See the figure below. Triangle \(A E H\), quadrilateral \(B F I E\), quadrilateral \(D H J G\), and pentagon \(F C G J I\) each has area \(1 .\) What is \(F I^2\)?
A
\(\dfrac{7}{3}\)
\(8 - 4 \sqrt{2}\)
Correct Answer
C
\(1 + \sqrt{2}\)
D
\(\dfrac{7}{4} \sqrt{2}\)
E
\(2 \sqrt{2}\)
No explanation
22 Number Theory
Wrong
What is the remainder when \(2^202 + 202\) is divided by \(2^101 + 2^51 + 1\)?
A
\(100\)
B
\(101\)
C
\(200\)
\(201\)
Correct Answer
E
\(202\)
No explanation
23 Counting and Probability
Wrong
Square \(A B C D\) in the coordinate plane has vertices at the points \(A ( 1 , 1 ) , B ( - 1 , 1 ) , C ( - 1 , - 1 ) ,\) and \(D ( 1 , - 1 ) .\) Consider the following four transformations: \(\quad bullet #h(2em) \) L ,\( a rotation of \)90^compose\( counterclockwise around the origin; \)quad bullet #h(2em) \( R ,\) a rotation of \(90^\circ\) clockwise around the origin; \(\quad bullet #h(2em) \) H ,\( a reflection across the \)x\(-axis; and \)quad bullet #h(2em) \( V ,\) a reflection across the \(y\)-axis. Each of these transformations maps the squares onto itself, but the positions of the labeled vertices will change. For example, applying \(R\) and then \(V\) would send the vertex \(A\) at \(( 1 , 1 )\) to \(( - 1 , - 1 )\) and would send the vertex \(B\) at \(( - 1 , 1 )\) to itself. How many sequences of \(20\) transformations chosen from \(\{ L , R , H , V \}\) will send all of the labeled vertices back to their original positions? (For example, \(R , R , V , H\) is one sequence of \(4\) transformations that will send the vertices back to their original positions.)
A
\(2^37\)
B
\(3 \cdot 2^36\)
\(2^38\)
Correct Answer
D
\(3 \cdot 2^37\)
E
\(2^39\)
No explanation
24 Number Theory
Wrong
How many positive integers \(n\) satisfy \( \dfrac{n + 1000}{70} = ⌊ \sqrt{n} ⌋ ? \) (Recall that \(⌊ x ⌋\) is the greatest integer not exceeding \(x\).)
A
\(2\)
B
\(4\)
\(6\)
Correct Answer
D
\(30\)
E
\(32\)
No explanation
25 Number Theory
Wrong
Let \(D ( n )\) denote the number of ways of writing the positive integer \(n\) as a product \( n = f_1 \cdot f_2 \cdots.c f_k , \) where \(k \geq 1\), the \(f_i\) are integers strictly greater than \(1\), and the order in which the factors are listed matters (that is, two representations that differ only in the order of the factors are counted as distinct). For example, the number \(6\) can be written as \(6\), \(2 \cdot 3\), and \(3 \cdot 2\), so \(D ( 6 ) = 3\). What is \(D ( 96 )\)?
\(112\)
Correct Answer
B
\(128\)
C
\(144\)
D
\(172\)
E
\(184\)
No explanation

Score History (Last 2)

0%
7/23
0%
7/27
# Date Score Accuracy
Current 2026-07-27 21:52 0 / 25 0%
2 2026-07-23 04:47 0 / 25 0% View