MathDB

Set 1
p1. Arnold is currently stationed at

(0, 0)

. He wants to buy some milk at

(3, 0)

, and also some cookies at

(0, 4)

, and then return back home at

(0, 0)

. If Arnold is very lazy and wants to minimize his walking, what is the length of the shortest path he can take?
p2. Dilhan selects

1

shirt out of

3

choices,

1

pair of pants out of

4

choices, and

2

socks out of

6

differently-colored socks. How many outfits can Dilhan select? All socks can be worn on both feet, and outfits where the only difference is that the left sock and right sock are switched are considered the same.
p3. What is the sum of the first

100

odd positive integers?
p4. Find the sum of all the distinct prime factors of

1591

.
p5. Let set

S = \{1, 2, 3, 4, 5, 6\}

. From

S

, four numbers are selected, with replacement. These numbers are assembled to create a

4

-digit number. How many such

4

-digit numbers are multiples of

3

?
Set 2
p6. What is the area of a triangle with vertices at

(0, 0)

(7, 2)

, and

(4, 4)

?
p7. Call a number

n

“warm” if

n - 1

n

, and

n + 1

are all composite. Call a number

m

“fuzzy” if

m

may be expressed as the sum of

3

consecutive positive integers. How many numbers less than or equal to

30

are warm and fuzzy?
p8. Consider a square and hexagon of equal area. What is the square of the ratio of the side length of the hexagon to the side length of the square?
p9. If

x^2 + y^2 = 361

xy = -40

, and

x - y

is positive, what is

x - y

?
p10. Each face of a cube is to be painted red, orange, yellow, green, blue, or violet, and each color must be used exactly once. Assuming rotations are indistinguishable, how many ways are there to paint the cube?
Set 3
p11. Let

D

be the midpoint of side

BC

of triangle

ABC

. Let

P

be any point on segment

AD

. If

M

is the maximum possible value of

\frac{[PAB]}{[PAC]}

and

m

is the minimum possible value, what is

M - m

?
Note:

[PQR]

denotes the area of triangle

PQR

.
p12. If the product of the positive divisors of the positive integer

n

n^6

, find the sum of the

3

smallest possible values of

n

.
p13. Find the product of the magnitudes of the complex roots of the equation

(x - 4)^4 +(x - 2)^4 + 14 = 0

.
p14. If

xy - 20x - 16y = 2016

and

x

and

y

are both positive integers, what is the least possible value of

\max (x, y)

?
p15. A peasant is trying to escape from Chyornarus, ruled by the Tsar and his mystical faith healer. The peasant starts at

(0, 0)

on a

6 \times 6

unit grid, the Tsar’s palace is at

(3, 3)

, the healer is at

(2, 1)

, and the escape is at

(6, 6)

. If the peasant crosses the Tsar’s palace or the mystical faith healer, he is executed and fails to escape. The peasant’s path can only consist of moves upward and rightward along the gridlines. How many valid paths allow the peasant to escape?
PS. You should use hide for answers. Rest sets have been posted [url=https://artofproblemsolving.com/community/c3h2784259p24464954]here. Collected [url=https://artofproblemsolving.com/community/c5h2760506p24143309]here.

Problem Statement