What is the divisibility rule for 2?
The last digit must end in 0, 2, 4, 6, or 8.
What is the divisibility rule for 3?
Sum all digits and divide by 3.
What is the divisibility rule for 4?
Divide the last two digits by 4.
What is the divisibility rule for 5?
The last digit ends in 0 or 5.
What is the divisibility rule for 6?
The number is divisible by 2 and 3.
What is the divisibility rule for 7?
No simple rule.
What is the divisibility rule for 8?
Divide the last 3 digits by 8.
What is the divisibility rule for 9?
Sum the digits of the number and divide by 9.
What are the parity rules for addition/subtraction?
o + o = e
e + e = e
e + o = o
What are the parity rules for multiplication?
o * o = o
e * (o or e) = e
What is the sum of consecutive even integers?
n(n+1), where n = the number of terms.
What is the sum of consecutive odd integers?
n^2, where n = the number of terms.
What is the sum of consecutive integers?
[n(n+1)]/2, where n = the number of terms.
How many integer terms are in a list m ... n?
How many integer terms are in a list m ... n with a difference of d?
(n-m)/d + 1
Given the same parameters which is greater combinations or permutations?
With permutations order matters, so they are greater in number than combinations. P(n,r) = n!/(n-r)! and C(n,r) = n!/r!(n-r)!.
What is the formula for permutations?
P(n,r) = n!/(n-r)!
What is the formula for combinations?
C(n,r) = n!/r!(n-r)!
How many primes exist between 1 and 100?
Name four common right triangle side triples. ( a, b, c)
(3,4,5), (5,12,13), (1,1,sqrt(2)), (1,sqrt(3),2)
A triangle with 3 equal sides and 3 equal angles is called?
An equilateral triangle
A triangle with 2 equal sides and 2 equal angles is called?
An Isoceles triangle
What is the exterior angle theorem?
The external angle A of triangle ABC is equal to the two opposite interior angles at B and C.
What is the triangle Inequality theorem?
Any one side of a triangle is less than the sum of the two other sides. a < b + c, b < a + c, c < a+b
What is the parallel line theorem?
if lines L1 // L2 is transversed by l3, angles 1,4,5,8 are equal and angles 2,3,6,7 are equal.
All triangles that have the same base and height have ___________.
For a fixed perimeter the circle has the _________ area.
For a fixed area, the circle has the _________ perimeter.
If an equilateral triangle has a side length x, the height is?
What is the area of a trapezoid?
1/2 * (b1 + b2)h
Opposite interior angles of a parallelogram are __________.
The sum of interior angles of a polygon is ______.
(n - 2)180
The sum of exterior angles of a polygon is ________.
How are permutations and combinations related?
C(n,r) = P(n,r) / r!
What is the sum of an arithmetic progression?
S = n/2[2a * (n-1)d]
What are the side ratios of a 30-60-90 right triangle?
(1, sqrt(3), 2)
What are the side ratios of a 45-45-90 right triangle?
(1, 1, sqrt(2))
Supplementary angles add up to ______ degrees.
Complementary angles add up to _____ degrees.
What is the sum of an Arithmetic Progression (AP)?
S = n/2[ 2a + (n-1)d]
What is the value of the nth term of an arithmetic progression?
an= a1 + (n-1)d, where an is the nth term, a1 is first term, and d is the difference.