Number System


  1. The sum of the numerator and denominator of a positive fraction is 11. If 2 is added to both numerator and denominator, the fraction is increased by 1/24.The difference of numerator and denominator of the fraction is









  1. View Hint View Answer Discuss in Forum

    Let numerator be x, then denominator = 11 – x.

    ∴  Fraction =
    x
    11 − x

    Again,
    x + 2
    11 − x + 2

    =
    x
    +
    1
    11 − x 24

    ⇒ 
    x + 2
    +
    x
    =
    1
    13 − x 11 − x24

    ⇒ 
    11x − x2 + 22 − 2x − 13x + x2
    =
    1
    (13 − x )(11 − x)24

    ⇒  528 – 96x = 143 – 24x + x2
    ⇒  x2 + 72x – 385 = 0
    ⇒  x2 + 77x – 5x – 385 = 0
    ⇒  x (x + 77) – 5 (x + 77) = 0
    ⇒  (x – 5) (x + 77) = 0 ⇒ x = 5
    ∴  Denominator = 11 – 5 = 6
    ∴  Difference = 6 – 5 = 1

    Correct Option: C

    Let numerator be x, then denominator = 11 – x.

    ∴  Fraction =
    x
    11 − x

    Again,
    x + 2
    11 − x + 2

    =
    x
    +
    1
    11 − x 24

    ⇒ 
    x + 2
    +
    x
    =
    1
    13 − x 11 − x24

    ⇒ 
    11x − x2 + 22 − 2x − 13x + x2
    =
    1
    (13 − x )(11 − x)24

    ⇒  528 – 96x = 143 – 24x + x2
    ⇒  x2 + 72x – 385 = 0
    ⇒  x2 + 77x – 5x – 385 = 0
    ⇒  x (x + 77) – 5 (x + 77) = 0
    ⇒  (x – 5) (x + 77) = 0 ⇒ x = 5
    ∴  Denominator = 11 – 5 = 6
    ∴  Difference = 6 – 5 = 1


  1. A fraction having denominator 30 and lying between 5/8 and 7/11 is -









  1. View Hint View Answer Discuss in Forum

    5
    = 0.625 ;
    7
    = 0.636
    811

    20
    = 0.666...;
    19
    = 0.633...
    3030

    Correct Option: B

    5
    = 0.625 ;
    7
    = 0.636
    811

    20
    = 0.666...;
    19
    = 0.633...
    3030



  1. How many 1/6 of together make
    41
    2
    ?
    3









  1. View Hint View Answer Discuss in Forum

    Required answer

    125/3
    =
    125
    × 6 = 250
    1/63

    Correct Option: C

    Required answer

    125/3
    =
    125
    × 6 = 250
    1/63


  1. A man spends
    1
    th of his income on food
    2
    rd of it on house rent and
    43
    the remaining income which is ₹ 630 on other commodities. Find his house rent.









  1. View Hint View Answer Discuss in Forum

    Suppose total income = ₹ p

    ∴  p −
    p
    2p
    = 630
    43

    p
    = 630   ∴ p = 7560
    12

    Correct Option: A

    Suppose total income = ₹ p

    ∴  p −
    p
    2p
    = 630
    43

    p
    = 630   ∴ p = 7560
    12

    ∴  House rent =
    2
    × 7560 = ₹ 5040
    3



  1. A tree increases annually by
    1
    th of its height. By how much will it
    8
    increase after 2 years, if it stands today 64 cm high?









  1. View Hint View Answer Discuss in Forum

    According to question ,

    Height of tree after 1 year = 64 + 64 ×
    1
    = 72 cm
    8

    Height of tree after 2 years = 72 + 72 ×
    1
    8

    Correct Option: D

    According to question ,

    Height of tree after 1 year = 64 + 64 ×
    1
    = 72 cm
    8

    Height of tree after 2 years = 72 + 72 ×
    1
    8

    Height of tree after 2 years = 72 + 9 = 81 cm