Simplification


  1. (53 × 87 + 159 × 21 + 106 × 25) is equal to









  1. View Hint View Answer Discuss in Forum

    Expression
    = (53 × 87 +159 ×21 + 106 × 25)
    = 53 (87 +3 ×21 + 2 × 25)
    = 53 (87 + 63 + 50)
    = 53 × 200 = 10600

    Correct Option: C

    Expression
    = (53 × 87 +159 ×21 + 106 × 25)
    = 53 (87 +3 ×21 + 2 × 25)
    = 53 (87 + 63 + 50)
    = 53 × 200 = 10600


  1. 1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    is equal to :
    3.55.77.99.1111.1313.15









  1. View Hint View Answer Discuss in Forum

    =
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    3.55.77.99.1111.1313.15

    =
    1
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    23.55.77.99.1111.1313.15

    =
    1
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    235577991111131315

    =
    1
    1
    1
    =
    1
    5 − 1
    2315215

    =
    1
    ×
    4
    =
    2
    21515


    Second Method :
    =
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    3.55.77.99.1111.1313.15

    Here, n = 3 and r = 6
    =
    1
    1
    1
    2nn + 2r

    =
    1
    1
    1
    233 + 2 × 6

    =
    1
    1
    1
    2315

    =
    1
    5 − 1
    =
    2
    21515

    Correct Option: D

    =
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    3.55.77.99.1111.1313.15

    =
    1
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    23.55.77.99.1111.1313.15

    =
    1
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    235577991111131315

    =
    1
    1
    1
    =
    1
    5 − 1
    2315215

    =
    1
    ×
    4
    =
    2
    21515


    Second Method :
    =
    1
    +
    1
    +
    1
    +
    1
    +
    1
    +
    1
    3.55.77.99.1111.1313.15

    Here, n = 3 and r = 6
    =
    1
    1
    1
    2nn + 2r

    =
    1
    1
    1
    233 + 2 × 6

    =
    1
    1
    1
    2315

    =
    1
    5 − 1
    =
    2
    21515



  1. (256)0.16 × (16)0.18 is equal to









  1. View Hint View Answer Discuss in Forum

    Expression
    = (256)0.16 × (16)0.18
    = (28)0.16 × (24)0.18
    = (2)8 × 0.16 × (2)4 × 0.18
    = (2)1.28 × (2)0.72 = (2)1.28 + 0.72
    =(2)2 = 4

    Correct Option: A

    Expression
    = (256)0.16 × (16)0.18
    = (28)0.16 × (24)0.18
    = (2)8 × 0.16 × (2)4 × 0.18
    = (2)1.28 × (2)0.72 = (2)1.28 + 0.72
    =(2)2 = 4


  1. The value of  3
    0.2 × 0.2 × 0.2 + 0.4 × 0.4 × 0.4
    is
    0.4 × 0.4 × 0.4 + 0.8 × 0.8 × 0.8









  1. View Hint View Answer Discuss in Forum

    Let 0.2 = a and 0.04 = b
    ⇒  0.4 = 2a and 0.08 = 2b

    ∴  Expression = 3
    a × a × a + b × b × b
    2a × 2a × 2a + 2b × 2b × 2b

    = 3
    a3 + b3
    8a3 + 8b3

    = 3
    1
    8

    =
    1
    = 0.5
    2

    Correct Option: A

    Let 0.2 = a and 0.04 = b
    ⇒  0.4 = 2a and 0.08 = 2b

    ∴  Expression = 3
    a × a × a + b × b × b
    2a × 2a × 2a + 2b × 2b × 2b

    = 3
    a3 + b3
    8a3 + 8b3

    = 3
    1
    8

    =
    1
    = 0.5
    2



  1. (0 . 05 × 5 – 0 . 005 × 5) equals









  1. View Hint View Answer Discuss in Forum

    Expression
    = 0.05 × 5 – 0.005 × 5
    = 0.25 – 0.025 = 0.225

    Correct Option: B

    Expression
    = 0.05 × 5 – 0.005 × 5
    = 0.25 – 0.025 = 0.225