MathDB

[hide=D stands for Dedekind, Z stands for Zermelo]they had two problem sets under those two names
D1. The product of two positive integers is

5

. What is their sum?
D2. Gavin is

4

feet tall. He walks

5

feet before falling forward onto a cushion. How many feet is the top of Gavin’s head from his starting point?
D3. How many times must Nathan roll a fair

6

-sided die until he can guarantee that the sum of his rolls is greater than

6

?
D4 / Z1. What percent of the first

20

positive integers are divisible by

3

?
D5. Let

a

be a positive integer such that

a^2 + 2a + 1 = 36

. Find

a

.
D6 / Z2. It is said that a sheet of printer paper can only be folded in half

7

times. A sheet of paper is

8.5

inches by

11

inches. What is the ratio of the paper’s area after it has been folded in half

7

times to its original area?
D7 / Z3. Boba has an integer. They multiply the number by

8

, which results in a two digit integer. Bubbles multiplies the same original number by 9 and gets a three digit integer. What was the original number?
D8. The average number of letters in the first names of students in your class of

24

7

. If your teacher, whose first name is Blair, is also included, what is the new class average?
D9 / Z4. For how many integers

x

9x^2

greater than

x^4

?
D10 / Z5. How many two digit numbers are the product of two distinct prime numbers ending in the same digit?
D11 / Z6. A triangle’s area is twice its perimeter. Each side length of the triangle is doubled,and the new triangle has area

60

. What is the perimeter of the new triangle?
D12 / Z7. Let

F

be a point inside regular pentagon

ABCDE

such that

\vartriangle FDC

is equilateral. Find

\angle BEF

.
D13 / Z8. Carl, Max, Zach, and Amelia sit in a row with

5

seats. If Amelia insists on sitting next to the empty seat, how many ways can they be seated?
D14 / Z9. The numbers

1, 2, ..., 29, 30

are written on a whiteboard. Gumbo circles a bunch of numbers such that for any two numbers he circles, the greatest common divisor of the two numbers is the same as the greatest common divisor of all the numbers he circled. Gabi then does the same. After this, what is the least possible number of uncircled numbers?
D15 / Z10. Via has a bag of veggie straws, which come in three colors: yellow, orange, and green. The bag contains

8

veggie straws of each color. If she eats

22

veggie straws without considering their color, what is the probability she eats all of the yellow veggie straws?
Z11. We call a string of letters purple if it is in the form

CVCCCV

, where

C

s are placeholders for (not necessarily distinct) consonants and

V

s are placeholders for (not necessarily distinct) vowels. If

n

is the number of purple strings, what is the remainder when

n

is divided by

35

? The letter

y

is counted as a vowel.
Z12. Let

a, b, c

, and d be integers such that

a+b+c+d = 0

and

(a+b)(c+d)(ab+cd) = 28

. Find

abcd

.
Z13. Griffith is playing cards. A

13

-card hand with Aces of all

4

suits is known as a godhand. If Griffith and

3

other players are dealt

13

-card hands from a standard

52

-card deck, then the probability that Griffith is dealt a godhand can be expressed in simplest form as

\frac{a}{b}

. Find

a

.
Z14. For some positive integer

m

, the quadratic

x^2 + 202200x + 2022m

has two (not necessarily distinct) integer roots. How many possible values of

m

are there?
Z15. Triangle

ABC

with altitudes of length

5

6

, and

7

is similar to triangle

DEF

. If

\vartriangle DEF

has integer side lengths, find the least possible value of its perimeter.
PS. You should use hide for answers. Collected [url=https://artofproblemsolving.com/community/c5h2760506p24143309]here.

Problem Statement