Gre General Test Math Flashcards

Front 1

What are the first 10 prime numbers?

Back 1

2, 3, 5, 7, 11, 13, 17, 19, 23, 29

Front 2

Adding Fractions:
5/6 + 2/3

Back 2

-Find the LCM:
5/6 + 2/3 LCM of 6 and 3 is 6
5/6 * 1/1 + 2/3 * 2/2 equals:
5/6 + 4/6 = 9/6 or 3/2

Front 3

Subtracting Fractions:
3/4 - 2/3

Back 3

-Find the LCM:
3/4 - 2/3 LCM of 4 & 3 is 12
3/4 * 3/3 - 2/3 * 4/4 equals:
9/12 - 8/12 = 1/12

Front 4

Dividing Fractions:
2/5 / 7/8

Back 4

-flip the fraction you're dividing by, then multiply:
2/5 / 7/8 = 2/5 * 8/7= 16/35

Front 5

Multiplying Fractions:
-10/4 * 3/5

Back 5

Simply Multiply:
-10/4 * 3/5 = -30/20 = -3/2

Front 6

How do you convert a mixed fraction into a pure fraction?
Ex: 3 2/7

Back 6

* integer by denominator & add product to numerator:
3 2/7 = 23/7

Front 7

How do you convert a fraction to a decimal?
Ex: 2/7

Back 7

Divide the top by the bottom:
2/7 = 7 divided by 2 = .28

Front 8

When can you add and subtract exponents?

Back 8

When they share the same base and the same power:
3x to the 2nd & 2x to the 2nd = 5x to the 2

Front 9

When can you multiply and divide exponents and roots?

Back 9

When they share a base:
x to the 2nd * x to the 3rd = x to the 5th
x to the 2nd / x to the 3rd = x to the 1st

Front 10

How do you raise the power of an exponent?
Ex: (x to the a)to the b
Ex: (x to the 2nd)to the 3rd

Back 10

(x to the a) to the b =
x to the ab
(x to the 2nd) to the 3rd =
x to the 6th

Front 11

What is the definition of a cube root?

Back 11

a # divided by itself twice
EX: the cube root of 27 is 3 because 27 / 3 = 9 and 9 / 3 = 3

Front 12

What is the square root of 9?

Back 12

The square root of 9 is 3

Front 13

Acute Angle

Back 13

An angle with less than 90 degrees

Front 14

Right Angle

Back 14

An angle measuring 90 degres

Front 15

Obtuse Angle

Back 15

An angle measuring more than 90 and less than 180 degrees

Front 16

Complementary Angles

Back 16

Angles whose sums measure 90 degrees

Front 17

Supplementary Angles

Back 17

Angles whose sums measure 180 degrees

Front 18

Adjacent Angles

Back 18

Angles who share a common side and a common vertex

Front 19

Vertical Angles

Back 19

Angles opposite each other when 2 straight lines intersect, forming 4 angles. They are always equal.

Front 20

Perpendicular Lines

Back 20

2 lines that meet to for right ngles.

Front 21

Parallel Lines

Back 21

Two or more lines that remain the same distance apart at all times.

Front 22

Corresponding Angles

Back 22

Identical angles

Front 23

Polygon

Back 23

Closed shape/figure in a plane with three or more sides

Front 24

Regular Polygon

Back 24

All sides have the same length and all angles have the same measure

Front 25

Convex Polygon

Back 25

All diagonals are within the figure

Front 26

Concave Polygon

Back 26

At least one diagonal is outside the figure

Front 27

Diagonals of Polygons

Back 27

Line segment connecting one vertex with another vertex. It isn't a side.

Front 28

Scalene Triangle

Back 28

A triangle with no equal sides

Front 29

Right Triangle

Back 29

A triangle with a right angle in its interior

Front 30

Every triangle has 3 ____ and 3 _______

Back 30

bases (bottom sides) and heights (altitudes), heights being the perpendicular distance from a vertext it its opposite side

Front 31

Triangle Median

Back 31

The line segment drawn from a vertext to the midpoint of the opposite side

Front 32

Rule for angles that are opposite from equl sides

Back 32

They are also equal

Front 33

Rule for the location of large and small angles in any triangle

Back 33

The longest side is always opposite from the largest angle. Same for the shortest.

Front 34

Rule for the sum of the lengths of the sides of a triangle

Back 34

The sum of the lengths of any 2 sides must be larger than the lengh of the 3rd side.

Front 35

Exterior Angle

Back 35

If 1 side of a triangle is extended, the exterior angle formed = the sum of the other 2 interior angles

Front 36

Hypotenuse

Back 36

The side opposite the right angle in a right triangle

Front 37

Pythagorean Theorem for right triangles

Back 37

the 3 lengths, a, b, and c will always be #'s such that:
a^2 + b^2 = c^2

Front 38

Isoceles Right Triangle

Back 38

Has characteristics of both isoceles/right triangles: 2 equal sides, 2 equal angles, and one right angle

Front 39

Rule for ratio of the sides of an isoceles right triangle

Back 39

The sides are always:
__
x, x, and X/2

Front 40

Ratio of the sides of a 30, 60, 90 triangle

Back 40

__
X, 2x, x/3
-Side opposite 30 is x, side opposite 60 is x/3, side opposite 90 is 2x

Front 41

Quadrilateral

Back 41

Polygon with 4 sides.
Sum of angles: 360

Front 42

Parallelogram

Back 42

-Opp. sides equal/parallel
-Angles equal
-Consecutive angles supplem.
-Diagonals not always equal

Front 43

Rhombus

Back 43

-Parallelogram w/4 equal sides
-Diagonals not always equal

Front 44

Trapezoid

Back 44

-1 pair of parallel sides

Front 45

Quadrilateral

Back 45

Polygon with 4 sides.
Sum of angles: 360

Front 46

Formula for Interior Angles of a polygon

Back 46

(n-2)180, n = the # of sides

Front 47

Parallelogram

Back 47

-Opp. sides equal/parallel
-Angles equal
-Consecutive angles supplem.
-Diagonals not always equal

Front 48

Rhombus

Back 48

-Parallelogram w/4 equal sides
-Diagonals not always equal

Front 49

Trapezoid

Back 49

-1 pair of parallel sides

Front 50

Formula for Interior Angles of a polygon

Back 50

(n-2)180, n = the # of sides

Front 51

Quadrilateral

Back 51

Polygon with 4 sides.
Sum of angles: 360

Front 52

Parallelogram

Back 52

-Opp. sides equal/parallel
-Angles equal
-Consecutive angles supplem.
-Diagonals not always equal

Front 53

Rhombus

Back 53

-Parallelogram w/4 equal sides
-Diagonals not always equal

Front 54

Trapezoid

Back 54

-1 pair of parallel sides

Front 55

Formula for Interior Angles of a polygon

Back 55

(n-2)180, n = the # of sides

Front 56

Quadrilateral

Back 56

Polygon w/4 sides
Sum of angles: 360 degrees

Front 57

Parallelogram

Back 57

Opp. sides are equal/parallel
Angles equal
Consec. angles supplementary
Diagonals not always equal

Front 58

Rhombus

Back 58

-Parallelogram with 4 equal sides
-Diagonals not always equal

Front 59

Trapezoid

Back 59

-1 pair of parallel sides

Front 60

Formula for interior angles of a polygon

Back 60

(n-2)180
n = the number of sides

Front 61

Formula for the perimeter of a polygon

Back 61

The sum of the sides

Front 62

Formula for the area of a triangle

Back 62

A= 1/2bh

Front 63

Formula for the area of a square/rectangle

Back 63

A= lw

Front 64

Formula for the area of a parallelogram

Back 64

A= bh

Front 65

Formula for the area of a trapezoid

Back 65

A= 1/2(b1 + b2)h

Front 66

Diameter

Back 66

Line containing the center of a circle with end points on the circle. All d's are equal length and equal 2(r)

Front 67

Chord

Back 67

Line segment whose endpoints lie on the circle

Front 68

Arc

Back 68

distance between any 2 points on the rim of the circle

Front 69

Formula for circumference of a circle

Back 69

C = 2(pi)(r), pi = 3.14

Front 70

Formula for area of a circle

Back 70

A = (pi)r^2

Front 71

Central Angle

Back 71

Angle formed by any 2 radii in a circle
c.a. = measure of intercepted arc

Front 72

Inscribed Angle

Back 72

the angle formed by any 2 chords that meet on the circle
i.a. = 1/2 measure of intercepted arc

Front 73

Formula for Calculating Interest

Back 73

principal * rate * time = Interest

Front 74

How do you change a fraction to a percent?
Ex: 2/5

Back 74

1. change to a decimal
2. Change the decimal to a percent
Ex: 2/5 = .4 = 40%

Front 75

How do you change a percent to a fraction?
Ex: 60%

Back 75

1. Drop the %
2. Write over 100
3. Reduce if necessary
Ex: 60% = 60/100 = 3/5

Front 76

How do you determine the percent of a number?
Ex: 20% of 80

Back 76

Change % to a fraction or decimal and multiply
20/100 * 80 = 1600/100 or 16

Front 77

18 is what percent of 90?

Back 77

18 = x(90)
18/90 = x
1/5 = x
20% = x

Front 78

10 is 50% of what number?

Back 78

10 = .50(x)
10/.50 = x
20 = x

Front 79

Formula for finding Percent Increase/Decrease
Ex: % decrease of a $500 item on sale for $400?

Back 79

change/starting point = % change
100/500 = 1/5 = 20%

Front 80

Inscribed angles

Back 80

angles formed by 2 chords of a circle that meet on the circle
They equal 1/2 measure of intercepted arc

Front 81

Concentric Circles

Back 81

Circles with the same center

Front 82

Tangent
2 Tangents drawn from the same point on a circle are...

Back 82

A line touching a circle at only 1 point
= in length and perpendic. to a radius meeting at that point

Front 83

Congruent geometric figures

Back 83

Identical in size and shape

Front 84

Similar geometric shapes

Back 84

Have the same shape but aren't identical in size

Front 85

Volume of a solid figure

Back 85

The # of cubic units of space the figure contains. AKA "cubic units".

Front 86

Formula for finding the area of a solid figure

Back 86

A = b * h

Front 87

Formula for the volume of a cube

Back 87

V = s * s * s = s^3

Front 88

Formula for the volume of a rectangular solid

Back 88

V = (lw)(h) = lwh

Front 89

Formula for the volume of a right circular cylinder (circular bases)

Back 89

V = (PIr^2)h = PIr^2h

Front 90

Raising a fraction b/t 0 and 1 results in a...
(1/2)^2 =

Back 90

Number smaller than 1:
(1/2)^2 = 1/4

Front 91

Factor

Factors of 12:

Back 91

A number that can be divided by another number without leaving a remainder:
2,3,3,4,6, 12

Front 92

Shortcut for comparing
3/7 and 7/14

Back 92

Multiply diagonally up from each denominator:
14 * 3 and 7 * 7

Front 93

Permutation

Back 93

Arrangement of things in a definite order:
4 factorial: 4 * 3 * 2 * 1

Front 94

Probability

Back 94

Equal to the outcome you're looking for divided by the total outcomes

Front 95

Reciprocal

Reciprocal of 1/2

Back 95

The inverse of something:

2/1

Front 96

Diameter

Back 96

A straight line segment passing through the center of the circle. It is 2 times the length of the radius