GMAT Fractions Refresher

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    Equivalent Fract ions

    GMAT

    Equivalent fractions can be created by multiplying/dividing the numerator and denominator by thsame number.

    1

    2

    1

    2

    3

    3

    3

    6

    Examples:

    5

    3

    7

    3

    7

    15

    5

    5

    3

    Multiply by 3 Multiply by 3

    1 3

    2 6

    Multiply by 5 Multiply by 5

    3 15

    7 35

    Practice: Fill in the blank

    a)

    b)

    c)

    d)

    e)

    f)

    g)

    h)

    i)

    j)

    1

    2 12

    Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    g)

    h)

    i)

    j)

    6

    6

    61

    2 12

    2

    3 24

    8

    8

    62

    3 24

    1

    4 16

    9

    4

    4

    6

    9 6

    4

    3

    1

    3

    5 60

    12

    1

    63

    5 02 6

    3

    1 7

    4

    7

    7

    7

    4 2

    1

    8

    5

    6 42

    7

    7

    55

    6 42

    3

    7 49

    8

    7

    7

    9

    8 6

    7

    5

    4

    2

    9 108

    12

    12

    22

    9 108

    4

    7

    15 135

    9

    9

    7

    15 135

    63

    1

    5 245

    49

    49

    41

    5 245

    9

    Fractions Refres

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    Simpl ifying Fractions

    To simplify a fraction, divide the numerator and denominator by the samenumber until the numerator and denominator can be simplified no further.

    8

    40

    56

    40

    5 86

    5

    7

    Examples:

    Divide by 8 Divide by 8

    42

    54

    42

    54

    21

    27

    21

    2

    2

    3

    27 3

    7

    9

    Divide by 2 Divide by 2

    Can be simplified further

    Divide by 3 Divide by 3

    Cannot be simplified further

    Practice: Simplify each fraction

    a)

    b)

    c)

    d)

    e)

    f)

    g)

    h)

    i)

    Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    g)

    h)

    i)

    Cannot be

    simplified further

    15

    20

    15

    20

    5 3

    45

    18

    27

    18

    27

    9 2

    39

    40

    48

    40

    48

    8 5

    68

    7

    13

    7

    13(already simplified

    60

    150

    60

    150

    30

    3

    2

    50

    39

    52

    39

    52

    13

    1

    3

    43

    135

    215

    135

    215

    7

    43

    5

    5

    2

    121

    154

    121

    154

    11

    11

    11

    14

    72

    108

    72

    108

    36

    3

    2

    36

    2

    5

    numerator

    denominator

    Fractions RefresGMAT

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    Converting Fractions

    Convert ing an entire f raction to a mixed fr action:

    1) Determine how many times the denominator divides into the numerator (this becomesthe whole number)

    2) The remainder becomes the numerator of the new fraction

    3) The denominator remains the same

    Entire fractions

    7

    2

    20

    3

    40

    17

    Mixed fractions

    13

    2

    26

    3

    62

    17

    Lets look at converting entire fractions to mixed fractions and converting mixed fractionsto entire fractions

    Examples: 7

    2 23

    1 The denominator (2) divides into the numerator (7) three

    times, with a remainder ofone

    32

    5 56 2 The denominator (5) divides into the numerator (32) six times,

    with a remainder oftwo

    51

    4 4

    21

    32

    7 7

    23

    Converting a m ixed fraction t o an entire fr action:

    1) Multiply the whole number by the denominator and add the product to the numerator

    2) The result becomes the new numerator and the denominator remains the same

    Examples: The whole number (5) multiplied by the denominator (4)equals 21. The denominator (4) remains the same

    The whole number (3) multiplied by the denominator (7)equals 22. The denominator (7) remains the same

    Practice questionson the next page

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    a)

    b)

    c)

    d)

    e)

    f)

    Practice: Convert each entire fraction to a mixed fraction Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    9

    4

    19

    5

    35

    2

    40

    7

    68

    11

    59

    6

    12

    4

    43

    5

    117

    2

    55

    7

    2

    6 11

    59

    6

    a)

    b)

    c)

    d)

    e)

    f)

    Practice: Convert each mixed fraction to an entire fraction Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    13

    4

    13

    4

    38

    5

    42

    9

    111

    15

    93

    20

    130

    3

    43

    5

    22

    9

    26

    15

    69

    20

    91

    3

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    Adding and subt racting fr act ions

    (1) Create equivalent fractions with the same denominator (a.k.a. common denominator)

    (2) Add/subtract the numerators, and keep the denominator the same

    Examples: 3 1

    4 6

    3 1

    4 6

    9

    3

    2

    12

    2

    3 2

    12

    11

    12

    Create equivalent fractions with the same denominator (12)

    Add the numerators; keep the denominator the same

    8 5

    9 12

    8 5

    9 12

    32 15

    36

    4

    36

    3

    4

    17

    36

    3

    Create equivalent fractions with the same denominator (36)

    Subtract the numerators; keep the denominator the same

    a)

    b)

    c)

    d)

    e)

    f)

    Practice: Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    3 1

    8 12

    14 7

    15 10

    7 3

    16 8

    1 2

    8 3

    1 51

    2 6

    5 9

    6 10

    11

    24

    7

    30

    1

    16

    19

    24

    2

    3

    26

    15

    111

    15or

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    Multiplying fr actions

    Multiply numerator by numerator, and denominator by denominator.

    9 4 36 3 16 3

    16 15 240 24

    2

    120 20

    Method 1:

    9 4 9 4 4 3 1 3

    16 15 16 1

    3

    5 4 5 204 3Cross simplify:

    Cross sim plif ying

    Whenever possible, cross simplify beforehand.

    2 5 10

    11 7 77

    5 1 5

    6 7 42

    Examples:

    a)

    b)

    c)

    d)

    e)

    f)

    Practice: Find each product and write answer in simplest terms Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    3 7

    5 9

    21 16

    32 35

    7 9

    24 14

    8 3

    15 4

    11 4

    16 33

    72 25

    125 96

    7

    15

    3

    10

    3

    16

    2

    5

    1

    12

    3

    20

    2

    5

    numerator

    denominator

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    Fractions Refres

    Dividing fractions

    Multiply by the reciprocal of the divisor.

    Examples:

    4 11

    9 20

    4 20

    9 11

    80

    99

    flip to become and multiply11

    20

    20

    11

    3 5

    7 8

    3 8

    7 5

    24

    35

    flip to become and multiply5

    8

    8

    5

    a)

    b)

    c)

    d)

    e)

    f)

    Practice: Find each quotient and write answer in simplest terms Answers:

    a)

    b)

    c)

    d)

    e)

    f)

    8

    21

    9 15

    16 16

    21 14

    40 25

    8 1

    15 20

    27 11

    32 8

    2 3

    7 4

    5 1

    6 5

    25

    6

    14

    6or

    3

    5

    15

    16

    32

    3

    210

    3or

    3

    4

    GMAT