Geometry
Number Theory
Algebra
Combinatorics
Probability
100

Name me as many ways to find the area of a triangle as you can! (Each correct answer gets 100 points).

Answers will vary but can include Herons, Base * Height, Product of inradius and the semiperimeter etc.

100

Let a, b, c, d, and e be distinct integers such that
(6−a)(6−b)(6−c)(6−d)(6−e)=45.What is a+b+c+d+e?

25

100

 is equal to:

2

100

Using the letters , , , , and , we can form five-letter "words". If these "words" are arranged in alphabetical order, then the "word"  occupies position

115

100

Each of two boxes contains three chips numbered , , . A chip is drawn randomly from each box and the numbers on the two chips are multiplied. What is the probability that their product is even?

5/9

200

In a triangle , ,  and . Points  and  lie on  and , respectively, with . Points  and  are on  so that  and  are perpendicular to . What is the area of a pentagon ?  

240/3

200

What is the remainder when 2025^(2025) is divided by 6? 

3

200

, what is the least value that  can be?

16

200

How many integers between 100 and 1000 contain the digit 2?

251

200

My soccer group often calls "best of five" to finish our games when it's getting dark, since we don't keep score. The game ends after one of the two teams scores three goals (total, not necessarily consecutive). If every possible sequence of scores is equally likely, what is the expected score of the losing team?

3/2

300

A circle centered at A with a radius of 1 and a circle centered at B with a radius of 4 are externally tangent. A third circle is tangent to the first two and to one of their common external tangents (Diagram will be provided on the board). The radius of the third circle is:

4/9

300

If n=2^(e1)⋅3^(e2)⋅5^(e3)⋯p^(ek) is the prime factorization of n, how many positive divisors does n have? (Do not have to fully simplify)

(e1+1)(e2+1)(e3+1).....(ek+1)

300

(2√6)/(√2+√3+√5) equals:

√2+√3−√5.

300

How many  four-digit integers have the property that their digits, read left to right, are in strictly decreasing order?

80

300

 Daniel chooses a real number uniformly at random from the interval [0, 2025]. Independently, William chooses a real number uniformly at random from the interval [0, 2050]. What is the probability that William's number is greater than Daniel's number? 

3/4

400

Equilateral  has side length , and squares , ,  lie outside the triangle. What is the area of hexagon ?

3 + sqrt (3)
400

There are  players in a single tennis tournament. The tournament is single elimination, meaning that a player who loses a match is eliminated. In the first round, the strongest  players are given a bye, and the remaining  players are paired off to play. After each round, the remaining players play in the next round. The match continues until only one player remains unbeaten. The total number of matches played is divisible by what prime number?

11

400

If a≥b>1, what is the largest possible value of   loga(a/b) + logb (b/a)? (In this case, since you can't write log base a, just consider loga as log base a and logb as log base b) BE READY TO EXPLAIN THE ANSWER!

0

400

When Martin walks up stairs, he takes one or two steps at a time. His stepping sequence is not necessarily regular. He could go up one step, the two steps, then two again, then one again, etc. How many ways can Martin walk up a 14-step stairwell?

610

400

The number  has over  positive integer divisors. One of them is chosen at random. What is the probability that it is odd?

1/19

500

A rectangular piece of paper whose length is  times the width has area . The paper is divided into three equal sections along the opposite lengths, and then a dotted line is drawn from the first divider to the second divider on the opposite side as shown. The paper is then folded flat along this dotted line to create a new shape with area . What is the ratio ?

2:3

500

Find the number of positive integers that are divisors of at least one of

435

500

Find all values of  that have the property that if  lies on the hyperbola , then so does the point .

3

500

In a drawer Sandy has  pairs of socks, each pair a different color. On Monday Sandy selects two individual socks at random from the  socks in the drawer. On Tuesday Sandy selects  of the remaining  socks at random and on Wednesday two of the remaining  socks at random. The probability that Wednesday is the first day Sandy selects matching socks is , where  and  are relatively prime positive integers, Find .

341

500

A coin is biased in such a way that on each toss the probability of heads is  and the probability of tails is . The outcomes of the tosses are independent. Even Ashoerae has the choice of playing Game A or Game B. In Game A he tosses the coin three times and wins if all three outcomes are the same. In Game B he tosses the coin four times and wins if both the outcomes of the first and second tosses are the same and the outcomes of the third and fourth tosses are the same. How do the chances of winning Game A compare to the chances of winning Game B?

 The probability of winning Game A is  greater than the probability of winning Game B.

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