Divisibility & Factorization
What is the greatest common divisor (GCD) of 84 and 126?
42
What is 15% of 80?
What comes next: 2, 6, 12, 20, 30, ___?
42
What is the sum of the interior angles of a hexagon?
Name one of our main lecturers
Edward Yang or Luke Liu
What is the smallest positive integer divisible by 6, 8, and 15?
120
A price is raised 20%, then the new price is cut 20%. The final price is what percent of the original?
96
The sequence 5, 9, 13, 17, … continues the same way. What is the 50th term?
201
A right triangle has legs 9 and 12. How long is the hypotenuse?
15
Which lesson did we cover divisibility?
Lesson 1
How many positive divisors does 360 have?
24
A class of 32 students has boys and girls in a 3 : 5 ratio. How many more girls than boys are there?
8
What is the units digit of 7 to the power of 2026?
9
How many diagonals does a decagon (10 sides) have?
35
How many 8th graders are in this class?
6
What is the smallest positive integer n such that n is divisible by 12 and has exactly 12 positive divisors?
60
What is 1+2/3+4/9+8/27... (infinitely many terms)?
3
What is 1+4+9+16...+99^2+100^2?
338350
(6,7),(m,2), and (2,m) are colinear. What are all values of m?
2, 11
How much hair does Luke have? (Right order of magnitude is correct)
100,000
What is the sum of all positive integers less than 100 that are divisible by neither 2 nor 3?
1633
Find 1/(1·2) + 1/(2·3) + … + 1/(9·10)
9/10
In the sequence 1, 1, 2, 3, 5, 8, …, how many of the first 100 terms are even?
33
A square is inscribed in a circle of radius 5. What is the area inside the circle but outside the square?
25pi-50
Recite 25 digits of pi.
3.141592653589793238462643