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Diophantine Equations: all problems

Focus mode: every practice problem from the chapter, one after another.

0 / 23 solved

Problem 21.5.1

AMC 8

Peter, Emma, and Kyler played chess with each other. Peter won 4 games and lost 2 games. Emma won 3 games and lost 3 games. If Kyler lost 3 games, how many games did he win?

Problem 21.5.2

AMC 8

The positive integers xx and yy are the two smallest positive integers for which the product of 360 and xx is a square and the product of 360 and yy is a cube. What is the sum of xx and yy?

Problem 21.5.3

AMC 8

How many digits are in the product 45⋅5104^5 \cdot 5^{10}?

Problem 21.5.4

AMC 8

For how many positive integer values of nn are both n3\frac{n}{3} and 3n3n three-digit whole numbers?

Problem 21.5.5

AMC 8

A 2-digit number is such that the product of the digits plus the sum of the digits is equal to the number. What is the units digit of the number?

Problem 21.5.6

AMC 8

In the multiplication problem below AA, BB, CC, DD are different digits. What is A+BA + B?

A B A×C DC D C D\begin{array}{r} A\,B\,A \\ \times \quad C\,D \\ \hline C\,D\,C\,D \end{array}

Problem 21.5.7

AMC 8

What is the correct ordering of the three numbers, 10810^8, 5125^{12}, and 2242^{24}?

Problem 21.5.8

AMC 8

Suppose aa, bb, and cc are nonzero real numbers, and a+b+c=0a + b + c = 0. What are the possible value(s) for a∣a∣+b∣b∣+c∣c∣+abc∣abc∣\frac{a}{|a|} + \frac{b}{|b|} + \frac{c}{|c|} + \frac{abc}{|abc|}?

(A) 0 (B) 1 and −1-1 (C) 2 and −2-2 (D) 0, 2, and −2-2 (E) 0, 1, and −1-1

Problem 21.5.9

AMC 8

After Euclid High School's last basketball game, it was determined that 14\frac{1}{4} of the team's points were scored by Alexa and 27\frac{2}{7} were scored by Brittany. Chelsea scored 15 points. None of the other 7 team members scored more than 2 points. What was the total number of points scored by the other 7 team members?

Problem 21.5.10

AMC 8

A baseball league consists of two four-team divisions. Each team plays every other team in its division N games. Each team plays every team in the other division M games with N>2MN > 2M and M>4M > 4. Each team plays a 76 game schedule. How many games does a team play within its own division?

Problem 21.5.11

AMC 10

What is the greatest three-digit positive integer nn for which the sum of the first nn positive integers is not a divisor of the product of the first nn positive integers?

Problem 21.5.12

AMC 8

How many perfect cubes lie between 28+12^8 + 1 and 218+12^{18} + 1, inclusive?

Problem 21.5.13

AIME

There is a prime number pp such that 16p+116p + 1 is the cube of a positive integer. Find pp.

Problem 21.5.14(additional)

After the digits of a 3 digit number are reversed, the number is 297 more than the original number. What's the largest possible value for the original number?

Problem 21.5.15(additional)

AMC 8

The hundreds digit of a three-digit number is 2 more than the units digit. The digits of the three-digit number are reversed, and the result is subtracted from the original three-digit number. What is the units digit of the result?

Problem 21.5.16(additional)

AMC 12

In multiplying two positive integers aa and bb, Ron reversed the digits of the two-digit number aa. His erroneous product was 161. What is the correct value of the product aa and bb?

Problem 21.5.17(additional)

AMC 12

A palindrome, such as 83438, is a number that remains the same when its digits are reversed. The numbers xx and x+32x + 32 are three-digit and four-digit palindromes, respectively. What is the sum of the digits of xx?

Problem 21.5.18(additional)

AMC 10

A two-digit positive integer is said to be cuddly if it is equal to the sum of its nonzero tens digit and the square of its units digit. How many two-digit positive integers are cuddly?

Problem 21.5.19(additional)

EMCC

What is the largest positive 2-digit factor of 322011−2220113^{2^{2011}} - 2^{2^{2011}}?

Problem 21.5.20(additional)

MATHCOUNTS

If mm and nn are positive integers where m2+14m−32=3nm^2 + 14m - 32 = 3^n, what is the value of m+nm + n?

Problem 21.5.21(additional)

AMC 10

Which of the following is equivalent to x1−x−1x\sqrt{\dfrac{x}{1 - \frac{x-1}{x}}} when x<0x < 0?

(A) −x-x (B) xx (C) 11 (D) x2\sqrt{\frac{x}{2}} (E) x−1x\sqrt{-1}

Problem 21.5.22(additional)

AMC 10

In the United States, coins have the following thicknesses: penny, 1.55 mm; nickel, 1.95 mm; dime, 1.35 mm; quarter, 1.75 mm. If a stack of these coins is exactly 14 mm high, how many coins are in the stack?

Problem 21.5.23(additional)

AMC 10

Boris has an incredible coin-changing machine. When he puts in a quarter, it returns five nickels; when he puts in a nickel, it returns five pennies; and when he puts in a penny, it returns five quarters. Boris starts with just one penny. Which of the following amounts could Boris have after using the machine repeatedly?

(A) $3.63 (B) $5.13 (C) $6.30 (D) $7.45 (E) $9.07