Ratio, Proportion


  1. Three numbers are in the ratio
    1
    :
    2
    :
    3
    .
    234
    The difference between the greatest and the smallest number is 36. The numbers are









  1. View Hint View Answer Discuss in Forum

    Ratio of numbers =
    1
    :
    2
    :
    3
    .
    234

    =
    1
    × 12 :
    2
    × 12 :
    3
    × 12
    234

    = 6 : 8 : 9
    Let the numbers be 6x, 8x and 9x.
    Now,  9x – 6x = 36
    ⇒  x = 12
    ∴  Numbers are
    72, 96 and 108.

    Correct Option: D

    Ratio of numbers =
    1
    :
    2
    :
    3
    .
    234

    =
    1
    × 12 :
    2
    × 12 :
    3
    × 12
    234

    = 6 : 8 : 9
    Let the numbers be 6x, 8x and 9x.
    Now,  9x – 6x = 36
    ⇒  x = 12
    ∴  Numbers are
    72, 96 and 108.


  1. Two numbers are in the ratio 2 : 3. If 2 is subtracted from the first and 2 is added to the second, the ratio becomes 1 : 2. The sum of the numbers is :









  1. View Hint View Answer Discuss in Forum

    Let the number be 2x and 3x.
    Then.

    2x − 2
    =
    1
    3x + 22

    ⇒  4x – 4 = 3x + 2
    ∴  x = 6
    ∴  Sum of Sum of numbers = 5x
    = 5 × 6 = 30

    Correct Option: A

    Let the number be 2x and 3x.
    Then.

    2x − 2
    =
    1
    3x + 22

    ⇒  4x – 4 = 3x + 2
    ∴  x = 6
    ∴  Sum of Sum of numbers = 5x
    = 5 × 6 = 30



  1. Of the three numbers, the ratio of the first and the second is 8 : 9 and that of the second and third is 3 : 4. If the product of the first and third number is 2400, then the second number is :









  1. View Hint View Answer Discuss in Forum

    Let the numbers be a, b and c.
    Now, a : b = 8 : 9
    b : c = 3 : 4
    ∴  a : b : c
    = 8 × 3 : 9 × 3 : 9 × 4
    = 24 : 27 : 36 = 8 : 9 : 12

    ∴ 
    a
    =
    b
    =
    c
    = k
    8912

    ⇒  a = 8k, b = 9k, c = 12k
    According to the question,
    8k × 12k = 2400
    ⇒  k2 =
    2400
    = 25
    8 × 12

    ⇒  k = 5
    ∴  Second number
    = 9k = 9 × 5 = 45

    Correct Option: A

    Let the numbers be a, b and c.
    Now, a : b = 8 : 9
    b : c = 3 : 4
    ∴  a : b : c
    = 8 × 3 : 9 × 3 : 9 × 4
    = 24 : 27 : 36 = 8 : 9 : 12

    ∴ 
    a
    =
    b
    =
    c
    = k
    8912

    ⇒  a = 8k, b = 9k, c = 12k
    According to the question,
    8k × 12k = 2400
    ⇒  k2 =
    2400
    = 25
    8 × 12

    ⇒  k = 5
    ∴  Second number
    = 9k = 9 × 5 = 45


  1. In a 45 litres mixture of milk and water, the ratio of the milk to water is 2 : 1. When some quantity of water is added to the mixture, this ratio becomes 1 : 2. The quantity of water added is









  1. View Hint View Answer Discuss in Forum

    Quantity of milk in 45 litres =
    2
    × 45 = 30 litres.
    3

    ∴  Water = (45 – 15)
    = 15 litres
    Let x litres of water be added.
    ∴ 
    30
    =
    1
    15 + x2

    ⇒  15 + x = 60
    ⇒  x = 60 – 15 = 45 litres.

    Correct Option: D

    Quantity of milk in 45 litres =
    2
    × 45 = 30 litres.
    3

    ∴  Water = (45 – 15)
    = 15 litres
    Let x litres of water be added.
    ∴ 
    30
    =
    1
    15 + x2

    ⇒  15 + x = 60
    ⇒  x = 60 – 15 = 45 litres.



  1. The sum of three numbers is 98. If the ratio of the first to the second is 2 : 3 and that of the second to the third is 5 : 8, then the second number is









  1. View Hint View Answer Discuss in Forum

    Let the numbers be x, y and z. Then
    x : y = 2 : 3 ; y : z = 5 : 8
    ∴  x : y : z = 2 × 5 : 3 × 5 : 3 × 8
    = 10 : 15 : 24
    Sum of the ratios
    = 10 + 15 + 24 = 49

    ∴  The second number =
    15
    × 45 = 30
    49

    Correct Option: C

    Let the numbers be x, y and z. Then
    x : y = 2 : 3 ; y : z = 5 : 8
    ∴  x : y : z = 2 × 5 : 3 × 5 : 3 × 8
    = 10 : 15 : 24
    Sum of the ratios
    = 10 + 15 + 24 = 49

    ∴  The second number =
    15
    × 45 = 30
    49