Ratio, Proportion


  1. What must be added to each term of the ratio 7 : 13, so that the ratio becomes 2 : 3 .









  1. View Hint View Answer Discuss in Forum

    Let x be added to each term .

    Then ,  
    7 + x
    =
    2
    13 + x3

    ⇒  3 (7 + x) = 2 (13 + x)
    ⇒  21 + 3x = 26 + 2x
    ⇒  3x – 2 x 26 – 21
    ⇒  x = 5
    ∴  5 must be added to each term .

    Correct Option: B

    Let x be added to each term .

    Then ,  
    7 + x
    =
    2
    13 + x3

    ⇒  3 (7 + x) = 2 (13 + x)
    ⇒  21 + 3x = 26 + 2x
    ⇒  3x – 2 x 26 – 21
    ⇒  x = 5
    ∴  5 must be added to each term .


  1. If
    x
    =
    2
    find the ratio of 9x + 6y : 5x + 3y .
    y5









  1. View Hint View Answer Discuss in Forum

    We have,  
    x
    =
    2
    y5

    ∴  9x + 6y : 5x + 3y =
    9x + 6y
    5x + 3y

    = 9
    x
    + 6
    y
    5
    x
    + 3
    y

    (On dividing Numerator and Denominator by y)
    = 9 ×
    2
    + 6
    5
    5 ×
    2
    + 3
    5

    =
    18 + 30
    5
    2 + 3

    =
    48
    =
    48
    5 × 525

    Correct Option: A

    We have,  
    x
    =
    2
    y5

    ∴  9x + 6y : 5x + 3y =
    9x + 6y
    5x + 3y

    = 9
    x
    + 6
    y
    5
    x
    + 3
    y

    (On dividing Numerator and Denominator by y)
    = 9 ×
    2
    + 6
    5
    5 ×
    2
    + 3
    5

    =
    18 + 30
    5
    2 + 3

    =
    48
    =
    48
    5 × 525



  1. If (2x + 3) : (5x – 38) be the duplicate ratio of √5 : √ 6 . Find the value of x .









  1. View Hint View Answer Discuss in Forum

    Since (2x + 3) : (5x – 38 ) is the duplicate ratio of √5 : √6,
    therefore

    2x + 3
    =
    5
    2
    5x − 386

    ⇒ 
    2x + 3
    =
    5
    5x − 386

    ⇒  6 (2x + 3)= 5 (5x – 38 )
    ⇒  12x + 18 = 25x – 190
    ⇒  25x – 12x = 18 + 190
    ⇒  13x = 208
    ⇒  x =
    208
    = 16
    13

    Correct Option: C

    Since (2x + 3) : (5x – 38 ) is the duplicate ratio of √5 : √6,
    therefore

    2x + 3
    =
    5
    2
    5x − 386

    ⇒ 
    2x + 3
    =
    5
    5x − 386

    ⇒  6 (2x + 3)= 5 (5x – 38 )
    ⇒  12x + 18 = 25x – 190
    ⇒  25x – 12x = 18 + 190
    ⇒  13x = 208
    ⇒  x =
    208
    = 16
    13


  1. If A : B = 1 : 2 , B : C = 3 : 4 , C : D = 2 : 3 and D : E = 3 : 4 , then find A : B : C : D : E .









  1. View Hint View Answer Discuss in Forum

    A : B = 1 : 2
    B : C = 3 : 4
    C : D = 2 : 3
    D : E = 3 : 4
    ∴  A : B : C : D : E
    = 1 × 3 × 2 × 3 : 2 × 3 × 2 × 3 : 2 × 4 × 2 × 3 : 2 × 4 × 3 × 3 : 2 × 4 × 3 × 4
    = 3 : 6 : 8 :12 : 1 6

    Correct Option: B

    A : B = 1 : 2
    B : C = 3 : 4
    C : D = 2 : 3
    D : E = 3 : 4
    ∴  A : B : C : D : E
    = 1 × 3 × 2 × 3 : 2 × 3 × 2 × 3 : 2 × 4 × 2 × 3 : 2 × 4 × 3 × 3 : 2 × 4 × 3 × 4
    = 3 : 6 : 8 :12 : 1 6



  1. If A : B = 3 : 4 , B : C = 8 : 10 and C : D = 15 : 17, th e n fin d A : B : C : D .









  1. View Hint View Answer Discuss in Forum

    A : B = 3 : 4 B : C = 8 : 1 0
    C : D = 15 : 17
    ∴  A : B : C : D = 3 × 8 × 15 : 4 × 8 × 15 : 4 × 10 × 15 : 4 × 10 × 17
    = 9 : 12 :15 : 17

    Correct Option: A

    A : B = 3 : 4 B : C = 8 : 1 0
    C : D = 15 : 17
    ∴  A : B : C : D = 3 × 8 × 15 : 4 × 8 × 15 : 4 × 10 × 15 : 4 × 10 × 17
    = 9 : 12 :15 : 17