Number System


  1. The value of λ for which the expression x3 + x2 – 5x + λ will be divisible by (x – 2) is :









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    (x – 2) is a factor of polynomial P (x) = x3 + x2 – 5x + λ.
    ∴  P(2) = 0 (on putting x = 2)

    Correct Option: B

    (x – 2) is a factor of polynomial P (x) = x3 + x2 – 5x + λ.
    ∴  P(2) = 0 (on putting x = 2)
    ⇒  23 + 22 – 5 × 2 + λ = 0
    ⇒  8 + 4 – 10 + λ = 0
    ⇒  λ + 2 = 0
    ∴  λ = - 2


  1. The number of integers in between 100 and 600, which are divisible by 4 and 6 both, is









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    We have to find such numbers which are divisible by 12 (LCM of 4 and 6).
    Number of numbers divisible by 12 and lying between 1 to 600

    =
    600
    −1 = 49
    12

    Number of numbers divisible by 12 from 1 to 100 =
    100
    = 8
    12

    Correct Option: C

    We have to find such numbers which are divisible by 12 (LCM of 4 and 6).
    Number of numbers divisible by 12 and lying between 1 to 600

    =
    600
    −1 = 49
    12

    Number of numbers divisible by 12 from 1 to 100 =
    100
    = 8
    12

    ∴ Required answer = 49 – 8 = 41



  1. A certain number when divided by 175 leaves a remainder 132. When the same number is divided by 25, the remainder is :









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    Here, first divisor (175) is a multiple of second divisor (25).
    ∴  Required remainder = Remainder obtained on dividing 132 by 25

    Correct Option: B

    Here, first divisor (175) is a multiple of second divisor (25).
    ∴  Required remainder = Remainder obtained on dividing 132 by 25
    ⇒ 132 = ( 25 × 6 ) + 7
    Thus , Required remainder is 7 .


  1. A number when divided by 280 leaves 115 as remainder. When the same number is divided by 35, the remainder is









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    According to question ,


    ∴  
    Number
    , remainder = 115
    280

    Here, 280 is a multiple of 35.

    Correct Option: B

    According to question ,


    ∴  
    Number
    , remainder = 115
    280

    Here, 280 is a multiple of 35.
    ∴ Required remainder = Remainder obtained on dividing 115 by 35
    ⇒ 115 = ( 35 × 3 ) + 10
    Thus , Required remainder is 10 .



  1. If the sum of the two numbers is 120 and their quotient is 5, then the difference of the two numbers is–









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    Let p and q are two numbers .
    According to question ,
    p + q = 120 ....... (i)

    p
    = 5
    q

    Correct Option: C

    Let p and q are two numbers .
    According to question ,
    p + q = 120 ....... (i)

    p
    = 5
    q

    ⇒ p = 5q
    From, equation (i),
    5q + q = 120
    ⇒ 6q = 120 ⇒  q = 20
    ∴ p = 120 – 20 = 100
    ∴  Required difference = 100 – 20 = 80