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2023 AMC 10B · #1Ratios, Percents & Averages

Mrs. Jones is pouring orange juice into four identical glasses for her four sons. She fills the first three glasses completely but runs out of juice when the fourth glass is only 13\frac{1}{3} full. What fraction of a glass must Mrs. Jones pour from each of the first three glasses into the fourth glass so that all four …

2023 AMC 10B · #2Ratios, Percents & Averages

Carlos went to a sports store to buy running shoes. Running shoes were on sale, with prices reduced by 20%20\% on every pair of shoes. Carlos also knew that he had to pay a 7.5%7.5\% sales tax on the discounted price. He had 4343 dollars. What is the original (before discount) price of the most expensive shoes he could …

2023 AMC 10B · #3Circles

A 3453-4-5 right triangle is inscribed in circle AA , and a 512135-12-13 right triangle is inscribed in circle BB . What is the ratio of the area of circle AA to the area of circle BB ?

2023 AMC 10B · #4Sets, Estimation & Miscellaneous

Jackson's paintbrush makes a narrow strip with a width of 6.56.5 millimeters. Jackson has enough paint to make a strip 2525 meters long. How many square centimeters of paper could Jackson cover with paint?

2023 AMC 10B · #5Linear Equations & Word Problems

Maddy and Lara see a list of numbers written on a blackboard. Maddy adds 33 to each number in the list and finds that the sum of her new numbers is 4545 . Lara multiplies each number in the list by 33 and finds that the sum of her new numbers is also 4545 . How many numbers are written on the blackboard?

2023 AMC 10B · #6Modular Arithmetic

Let L1=1L_1 = 1 , L2=3L_2 = 3 , and Ln+2=Ln+1+LnL_{n+2} = L_{n+1}+L_n for n1n \geq 1 . How many terms in the sequence L1,L2,L3,,L2023L_1, L_2, L_3, \cdots, L_{2023} are even?

2023 AMC 10B · #7Transformations & Symmetry

Square ABCDABCD is rotated 2020^{\circ} clockwise about its center to obtain square EFGHEFGH , as shown below. What is the degree measure of EAB\angle{EAB} ?

2023 AMC 10B · #8Modular Arithmetic

What is the units digit of 20222023+202320222022^{2023} + 2023^{2022} ?

2023 AMC 10B · #9Number Properties

The numbers 1616 and 2525 are a pair of consecutive positive squares whose difference is 99 . How many pairs of consecutive positive perfect squares have a difference of less than or equal to 20232023 ?

2023 AMC 10B · #10Paths & Grids

You are playing a game. A 22 ×\times 11 rectangle covers two adjacent squares (oriented either horizontally or vertically) of a 33 ×\times 33 grid of squares, but you are not told which two squares are covered. Your goal is to find at least one square that is covered by the rectangle. A "turn" consists of you …

2023 AMC 10B · #11Diophantine Equations

Suzanne went to the bank and withdrew $800\$800 . The teller gave her this amount using $20\$20 bills, $50\$50 bills, and $100\$100 bills, with at least one of each denomination. How many different collections of bills could Suzanne have received?

2023 AMC 10B · #12Polynomials

When the roots of the polynomial P(x)=(x1)1(x2)2(x3)3(x10)10P(x) = (x-1)^1 (x-2)^2 (x-3)^3 \cdot \cdot \cdot (x-10)^{10} are removed from the number line, what remains is the union of 1111 disjoint open intervals. On how many of these intervals is P(x)P(x) positive?

2023 AMC 10B · #13Absolute Value & Inequalities

What is the area of the region in the coordinate plane defined by x1+y11?| | x | - 1 | + | | y | - 1 | \le 1?

2023 AMC 10B · #14Diophantine Equations

How many ordered pairs of integers (m,n)(m,n) satisfy the equation m2+mn+n2=m2n2m^2+mn+n^2 = m^2n^2 ?

2023 AMC 10B · #15Number Properties

What is the least positive integer mm such that m2!3!4!5!16!m \cdot 2! \cdot 3!\cdot 4!\cdot 5! \dots 16! is a perfect square?

2023 AMC 10B · #16Basic Counting

Define an upnoupno to be a positive integer of 22 or more digits where the digits are strictly increasing moving left to right. Similarly, define a downnodownno to be a positive integer of 22 or more digits where the digits are strictly decreasing moving left to right. For instance, the number 258258 is an upno and 86208620

2023 AMC 10B · #17Algebraic Manipulation

A rectangular box PP has distinct edge lengths aa , bb , and cc . The sum of the lengths of all 1212 edges of PP is 1313 , the sum of the areas of all 66 faces of PP is 112\dfrac{11}{2} , and the volume of PP is 12\dfrac{1}{2} . What is the length of the longest interior diagonal connecting two vertices of PP ?

2023 AMC 10B · #18GCD & LCM

Suppose aa , bb , and cc are positive integers such that a14+b15=c210.\dfrac{a}{14}+\dfrac{b}{15}=\dfrac{c}{210}. Which of the following statements are necessarily true? I. If gcd(a,14)=1\gcd(a,14)=1 or gcd(b,15)=1\gcd(b,15)=1 or both, then gcd(c,210)=1\gcd(c,210)=1 . II. If gcd(c,210)=1\gcd(c,210)=1 , then gcd(a,14)=1\gcd(a,14)=1 or gcd(b,15)=1\gcd(b,15)=1 or both. III. …

2023 AMC 10B · #19Geometric Probability

Sonya the frog chooses a point uniformly at random lying within the square [0,6][0, 6] ×\times [0,6][0, 6] in the coordinate plane and hops to that point. She then randomly chooses a distance uniformly at random from [0,1][0, 1] and a direction uniformly at random from {north, south, east, west}. All her choices are …

2023 AMC 10B · #20Solid Geometry

Four congruent semicircles are drawn on the surface of a sphere with radius 22 , as shown, creating a close curve that divides the surface into two congruent regions. The length of the curve is πn\pi\sqrt{n} . What is nn ?

2023 AMC 10B · #21Conditional Probability & States

Each of 20232023 balls is randomly placed into one of 33 bins. Which of the following is closest to the probability that each of the bins will contain an odd number of balls?

2023 AMC 10B · #22Number Properties

How many distinct values of xx satisfy x23x+2=0,\lfloor{x}\rfloor^2-3x+2=0, where x\lfloor{x}\rfloor denotes the largest integer less than or equal to xx ?

2023 AMC 10B · #23Sequences & Series

An arithmetic sequence of positive integers has n3n\ge3 terms, initial term aa , and common difference d>1d>1 . Carl wrote down all the terms in this sequence correctly except for one term, which was off by 11 . The sum of the terms he wrote down was 222222 . What is a+d+na+d+n ?

2023 AMC 10B · #24Coordinate Geometry

What is the perimeter of the boundary of the region consisting of all points which can be expressed as (2u3w,v+4w)(2u-3w, v+4w) with 0u10\le u\le1 , 0v1,0\le v\le1, and 0w10\le w\le1 ?

2023 AMC 10B · #25Angles & Polygons

A regular pentagon with area 1+51+\sqrt5 is printed on paper and cut out. All five vertices are folded to the center of the pentagon, creating a smaller pentagon. What is the area of the new pentagon?