Formulas Flashcards
Formula: Area of a triangle
1/2 base x height
Pythagorean theorem?
a^2 +b^2 = c^2
1/8
- 5%
0. 125
1/6
- 6% (repeating)
0. 16 (6 repeating)
1/5
20%
0.2
1/4
25%
0.25
1/3
- 3% (repeating)
0. 3 (3 repeating)
3/8
- 5%
0. 375
2/5
40%
0.4
1/2
50%
0.5
3/5
60%
0.6
5/8
- 5%
0. 625
2/3
66.6% (repeating)
0.6 (6 repeating)
memory trick: 2 out of 3 IS bad… 66.6 ;)
3/4
75%
0.75
4/5
80%
0.8
5/6
- 3% (repeating)
0. 83 (3 repeating)
7/8
- 5%
0. 875
Find PERCENT given part and whole
ex:
What Percent of 60 is 45?
Percent= Part/Whole
or
Part/Whole =Percent
Part=45
Whole=60
Percent= ?
45/60=3/4= .75 = 75%
Sum of values given the average and number of values
Sum of values=
average value) X (number of values
Average rate…
If j travels 30 mph in 2 hrs and then
60 mph In 3 hours, what is his average speed in miles per hour?
Average A per B=
total A/ total B
Avg miles per hour=
Total miles/ Total hours
(30+60) miles/ (2+3) hours
90 miles/ 5 hrs= 18 miles/hour
The sum or difference between two odd or two even numbers is ______
Even
Odd +/- Odd= Even
Even +/- Even= Even
The product of an even number and any other number is _____.
Even
Even x Even= Even
Even x Odd=Even
Quadrilaterals:
Sum of interior angles
360 degrees
Area:
Square
Area of square= s^2
Area:
Rectangle
Area rectangle=lw
Every prime number ends in
1, 3, 7, and 9 with the exception of 2 and 5
Is it prime? Check if number is divisible by: (5 numbers)
2, 3, 5, 7 or 11
16.6% (repeating)
1/6
.16 repeating
12.5%
1/8
.125
1/8
12.5%
37.5%
3/8
60%
3/5
62.5%
5/8
11²
121
12²
144
13²
169
14²
196
15²
225
10²
100
Median of n numbers..
If n is odd…
If n is even….
Median of n numbers..
If n is odd..The median is the middle #
If n is even….there are two middle numbers and the median is the average of those two numbers
x² - y²=
x² - y²= (x+y)(x-y)
203² - 201² =
(203+201)(203-201)=
(404)(2)=808
B/c:
x² - y²= (x+y)(x-y)
If the numbers in a set are equally spaced the ___ and ____ of the set are the same
Mean and median
Set X: {-27, -20, -13, -6, 1, 8, 15}
Set Y: {-23, -19, -15, -11, -7, -3, 1, 5, 9, 13}
Column A Column B
Mean of set X Mean of set Y
A. The quantity in Column A is greater
B. The quantity in Column B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
Column A: Since the numbers in set X are equally spaced, the mean will equal the median. We can quickly find the median by locating the middlemost element: {-27, -20, -13, -6, 1, 8, 15}. Set X has 7 elements and the middlemost element is -6. So, the median of set X is -6, which means the mean of set X is -6 as well.
Column B: The numbers in set Y are also equally spaced, so the mean will equal the median. Set Y has 10 elements, so there are two middlemost elements: {-23, -19, -15, -11, -7, -3, 1, 5, 9, 13}. As such, the median of set Y will equal the average (mean) of -7 and -3, which is -5. So, if the median of set Y is -5, then the mean of set Y is -5 as well
Set T consists of all multiples of 5 from 30 to 225 inclusive
Column A Column B
Mean of Set T Median of Set T
A. The quantity in Column A is greater
B. The quantity in Column B is greater
C. The two quantities are equal
D. The relationship cannot be determined from the information given
If the numbers in a set are equally spaced, then the mean and median of that set are equal.
Answer is C
For all integers n ≥ 1…
A(n) = 9(n) + 3
Determine one of the first ten terms in this sequence.
*n is subscript
The nth term of this sequence is defined by the rule
9n + 3, for integers n ≥ 1. For example, the fourth term in this sequence is 9n + 3 = 9( 4) + 3 = 39. The first ten terms of the sequence are as follows: 12, 21, 30, 39, 48, 57, 66, 75, 84, 93
