1. Let the length of model ship be x Length of actual ship (in m) 12 28 Length of model ship (in cm) 9 x Here length of mast and actual length of ship are in direct proportion. ∴ 12/9 = 28/x ⇒ xX12=28x9 ⇒ x=28x9/12=21 cm Hence, the length of the model ship is 21 cm. Class 8 Maths Chapter 11 Exercise 13Read more

    Let the length of model ship be x
    Length of actual ship (in m) 12 28
    Length of model ship (in cm) 9 x
    Here length of mast and actual length of ship are in direct proportion.

    ∴ 12/9 = 28/x ⇒ xX12=28×9 ⇒ x=28×9/12=21 cm
    Hence, the length of the model ship is 21 cm.

    Class 8 Maths Chapter 11 Exercise 13.1 Solution in Video

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/

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  2. Let enlarged length of bacteria be x . Actual length of bacteria = 5/5000 = 1/10000 cm=10⁻⁴ Length 5 x Enlarged length 50,000 20,000 Here length and enlarged length of bacteria are in direct proportion. ∴ 5/50000 = x/20000 ⇒ xX50000 = 5x20000 ⇒ x= 5x20000/50000 = 2cm Hence, the enlarged length of baRead more

    Let enlarged length of bacteria be x .
    Actual length of bacteria = 5/5000 = 1/10000 cm=10⁻⁴

    Length 5 x
    Enlarged length 50,000 20,000
    Here length and enlarged length of bacteria are in direct proportion.

    ∴ 5/50000 = x/20000 ⇒ xX50000 = 5×20000 ⇒ x= 5×20000/50000 = 2cm
    Hence, the enlarged length of bacteria is 2 cm.

    Class 8 Maths Chapter 11 Exercise 13.1 Solution in Video

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/

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  3. Let the number of bottles filled in five hours be x. Hours 1 x Bottles 75 1800 Here ratio of hours and bottles are in direct proportion. ∴ 6/840 = 5/x ⇒ 6Xx = 5x840 ⇒ x=5x840/6 = 700 bottles Hence, machine will fill 700 bottles in five hours. Class 8 Maths Chapter 11 Exercise 13.1 Solution in VideoRead more

    Let the number of bottles filled in five hours be x.
    Hours 1 x
    Bottles 75 1800
    Here ratio of hours and bottles are in direct proportion.
    ∴ 6/840 = 5/x ⇒ 6Xx = 5×840 ⇒ x=5×840/6 = 700 bottles
    Hence, machine will fill 700 bottles in five hours.

    Class 8 Maths Chapter 11 Exercise 13.1 Solution in Video

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/

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  4. Let the parts of red pigment mix with 1800 mL base be x. Parts of red pigment 1 x Parts of base 75 1800 Since it is in direct proportion. ∴ 1/75 = x/1800 ⇒ 75Xx=1x1800 ⇒ x= 1x1800/75=24 Hence, with base 1800 mL, 24 parts red pigment should be mixed. Class 8 Maths Chapter 11 Exercise 13.1 Solution inRead more

    Let the parts of red pigment mix with 1800 mL base be x.

    Parts of red pigment 1 x
    Parts of base 75 1800
    Since it is in direct proportion.
    ∴ 1/75 = x/1800 ⇒ 75Xx=1×1800 ⇒ x= 1×1800/75=24
    Hence, with base 1800 mL, 24 parts red pigment should be mixed.

    Class 8 Maths Chapter 11 Exercise 13.1 Solution in Video

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/

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  5. Let the ratio of parts of red pigment and parts of base be a/b Here a₁=1,b₁=8 ⇒ a₁/b₁=1/8=k (say) When a₂=4,b₂=? k= a₂/b₂ ⇒ b₂= a₂/k =4/1/8 = 4/8 =32 When a₃=7,b₃=? k=a₃/b₃ ⇒ a₃=a₃/k = 7/1/8 = 7x8=56 When a₄=12,b₄=? k=a₄/b₄ ⇒ b₄=a₄/k= 12/1/8=12x8 =96 When a₅=20, b₅=? k=a₅/b₅ ⇒ b₅ = a₅/k =20/1/8 = 20Read more

    Let the ratio of parts of red pigment and parts of base be a/b
    Here a₁=1,b₁=8 ⇒ a₁/b₁=1/8=k (say)

    When a₂=4,b₂=?
    k= a₂/b₂ ⇒ b₂= a₂/k =4/1/8 = 4/8 =32

    When a₃=7,b₃=?
    k=a₃/b₃ ⇒ a₃=a₃/k = 7/1/8 = 7×8=56

    When a₄=12,b₄=?
    k=a₄/b₄ ⇒ b₄=a₄/k= 12/1/8=12×8 =96

    When a₅=20, b₅=?
    k=a₅/b₅ ⇒ b₅ = a₅/k =20/1/8 = 20×8=160

    Parts of red pigment 1 4 7 12 20
    Parts of base 8 32 56 96 160

    Class 8 Maths Chapter 11 Exercise 13.1 Solution in Video

    for more answers vist to:
    https://www.tiwariacademy.com/ncert-solutions/class-8/maths/chapter-13/

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