WHOLEsome:)
geometry
Probably fun
number theory
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100

At a gathering of  people, there are  people who all know each other and  people who know no one. People who know each other hug, and people who do not know each other shake hands. How many handshakes occur?

245

100

Line  has equation  and goes through . Line  has equation  and meets line  at point . Line  has positive slope, goes through point , and meets  at point . The area of  is . What is the slope of ?

3/4

100

When  fair standard -sided dice are thrown, the probability that the sum of the numbers on the top faces is  can be written aswhere  is a positive integer. What is ?

84

100

How many positive integers  satisfy the following condition:

125

100

The solution of the equation  can be expressed in the form . What is ?

8/7

200

Find the smallest prime that is the fifth term of an increasing arithmetic sequence, all four preceding terms also being prime.

29

200

Claire adds the degree measures of the interior angles of a convex polygon and arrives at a sum of . She then discovers that she forgot to include one angle. What is the degree measure of the forgotten angle?

143

200

Chloe chooses a real number uniformly at random from the interval . Independently, Laurent chooses a real number uniformly at random from the interval . What is the probability that Laurent's number is greater than Chloe's number?

3/4

200

Let  and  be two-digit integers such that  is obtained by reversing the digits of . The integers  and  satisfy  for some positive integer . What is ?

154

200

If log(xy3 ) = 1 and log(x 2y) = 1, what is log(xy)?

3/5

300

What is the sum of the exponents of the prime factors of the square root of the largest perfect square that divides  ?

8

300

In triangle  the medians  and  to sides  and , respectively, intersect in point .  is the midpoint of side , and  intersects  in . If the area of triangle  is , then the area of triangle  is:

24n

300

A number  is randomly selected from the set , and a number  is randomly selected from . What is the probability that  has a units digit of ?

2/5

300

The integer  is the smallest positive multiple of  such that every digit of  is either  or . Compute .

592

300

Positive real numbers  and  have the property that

and all four terms on the left are positive integers, where  denotes the base- logarithm. What is ?

10^164

400

Cozy the Cat and Dash the Dog are going up a staircase with a certain number of steps. However, instead of walking up the steps one at a time, both Cozy and Dash jump. Cozy goes two steps up with each jump (though if necessary, he will just jump the last step). Dash goes five steps up with each jump (though if necessary, he will just jump the last steps if there are fewer than 5 steps left). Suppose that Dash takes 19 fewer jumps than Cozy to reach the top of the staircase. Let  denote the sum of all possible numbers of steps this staircase can have. What is the sum of the digits of ?

13

400

Triangle  has right angle at , and contains a point  for which , , and . Find .


33

400

James writes down fifteen 1's in a row and randomly writes + or - between each pair of consecutive 1's. One such example isWhat is the probability that the value of the expression James wrote down is ?

1001/2^14

400

Find all primes  such that there exist positive integers  that satisfy .

2,3,7

400

What is the value of

21,000

500

Ten identical crates each of dimensions . The first crate is placed flat on the floor. Each of the remaining nine crates is placed, in turn, flat on top of the previous crate, and the orientation of each crate is chosen at random. Let  be the probability that the stack of crates is exactly  tall, where  and  are relatively prime positive integers. Find .

190

500

A circle of radius  has chords  of length  and  of length 7. When  and  are extended through  and , respectively, they intersect at , which is outside of the circle. If  and , then

73

500

An urn contains  green balls and  blue balls. A second urn contains  green balls and  blue balls. A single ball is drawn at random from each urn. The probability that both balls are of the same color is . Find .

144

500

How many positive integers  less than  are there such that the equation  has a solution for ?

412


500

The value of  that satisfies  can be written as , where  and  are relatively prime positive integers. Find .

103