Algebra
Geometry
Combinatorics
Number Theory
Mystery
100

If 3x - 7 = 23, what is x?

10

100

How many sides does a hexagon have?

5

100

On a fair six-sided die, what is the probability of rolling a 4?

1/6

100

What is 338 in base 10? (The 8 stands for the base.)

27

100

How many legs does a spider have?

8

200

I have a few marbles. If I borrow 3 more from my friend, but give half of my total after that to my brother, I will end up with 5 marbles left. How many marbles did I start with?

7

200

I take a square with side length 5 and attach an equilateral triangle on each side. What is the perimeter of the resulting figure?

40

200

I have 4 distinct cards. How many ways are there for me to pick 2 of them?

6

200

I have a favorite positive integer. If I divide it by 3, I get a remainder of 2. If I divide it by 4, I get a remainder of 3. What is the smallest possible value of my number?

11

200

An alien species has invaded Earth! They have 7 hands each and pick up 2 humans with each hand. How many humans will 5 of these monstrosities be holding?

70

300

What are the roots of the equation 6x^2 + 11x - 35 = 0?

-7/2 and 5/3

300

I have a triangle ABC where B is a right angle, AB = 3, and BC = 4. I then draw another triangle ADC where angle DAC is a right angle, and AD = 12. What is CD?

13

300

I roll 3 fair 6-sided dice, and I add the results. How many possible results are there?

16

300

If we split 1000 into two positive integer factors, neither of which contains a 0, what is their sum?

133

300

When is Alvin's birthday? (Closest guess wins.)

March 3
400

If the roots to the equation are 3x^2 + 7x + 2 = 0 can be expressed as r and s, what is r^2 + s^2?

37/9

400

What is the area of a regular hexagon with perimeter 36? Express your answer as a radical in simplest form.

Note: The area of an equilateral triangle with side length a can be expressed as (a^2)sqrt3/4.

54sqrt3

400

One mathematician asks another mathematician, "Do you have two children, at least one of which is a girl?"

The other person responds, "Yes."

What is the probability that they have two girls?

(Assume that the chances of having a girl is 50%.)

1/3

400

What is the units digit of 1! + 2! + 3! ... + 100!

3

400

How long will it take for me to count to 50 as fast as I can? (Closest guess wins!)

I don't know, let's find out! :)

500

A cyclist travels 40 miles at a constant speed. On the way back, they increase their speed by 2 mph, which makes the return trip take 1 hour less than the original trip. What was the original speed?

8 mph

500

A cylinder has a height of 10 cm and a radius of 3 cm. Inside it, there is a heavy metal sphere with a radius of 3 cm resting at the bottom.

If you fill the cylinder with water until it reaches the very top, what is the volume of the water? Express your answer in terms of pi.

54pi

500

A box contains n pens. There are 3 more black pens than red pens. If you take two pens without replacement, the probability of getting a black pen then a red pen is 9/35. What is n?

15

500

A five-digit number A28B7 is divisible by 9. If A and B are non-zero digits, how many different pairs of (A, B) are possible?

9
500

How many characters (including spaces) are in the following sentence? 

This may be a trick question...

23

M
e
n
u