Simplification


  1. The sum of the digits of the smallest number which, when multiplied by 1800, gives a perfect cube, is :









  1. View Hint View Answer Discuss in Forum

    1800 = 2 × 2 × 2 × 3 × 3 × 5 × 5 = 23 × 32 × 52
    To make 1800 a perfect cube, it must be multiplied by 15 (least number).
    ∴  Required sum = 1 + 5 = 6

    Correct Option: C

    1800 = 2 × 2 × 2 × 3 × 3 × 5 × 5 = 23 × 32 × 52
    To make 1800 a perfect cube, it must be multiplied by 15 (least number).
    ∴  Required sum = 1 + 5 = 6


  1. Sum of digits of the smallest number by which 1440 be multiplied so that it becomes a perfect cube, is









  1. View Hint View Answer Discuss in Forum

    1440 = 2 × 2 × 2 × 2 × 2 × 3 × 3 × 5 = 23 × 22 × 32 × 5
    To make 1440 a perfect cube, it must be mulitplied by 2 × 3 × 5 × 5 = 150.
    ∴  The required sum = 1+5 + 0 = 6

    Correct Option: B

    1440 = 2 × 2 × 2 × 2 × 2 × 3 × 3 × 5 = 23 × 22 × 32 × 5
    To make 1440 a perfect cube, it must be mulitplied by 2 × 3 × 5 × 5 = 150.
    ∴  The required sum = 1+5 + 0 = 6



  1. By which smallest number 1323 must be multiplied, so that it becomes a perfect cube?









  1. View Hint View Answer Discuss in Forum

    1323 = 3 × 3 × 3 × 7 × 7
    ∴  It must be multiplied by 7.

    Correct Option: D

    1323 = 3 × 3 × 3 × 7 × 7
    ∴  It must be multiplied by 7.


  1. 3 4
    12
      is equal to
    125









  1. View Hint View Answer Discuss in Forum

    Expression = 3 4
    12
    125

    = 3
    512
    = 3
    8 × 8 × 8
    1255 × 5 × 5

    =
    8
    = 1.6
    5

    Correct Option: B

    Expression = 3 4
    12
    125

    = 3
    512
    = 3
    8 × 8 × 8
    1255 × 5 × 5

    =
    8
    = 1.6
    5



  1. The value of   (√43 + 152)3   is









  1. View Hint View Answer Discuss in Forum

    Expression = (√43 + 152)3
    = (√64 + 225)3 = (√289)3
    = (17)3 = 4913

    Correct Option: A

    Expression = (√43 + 152)3
    = (√64 + 225)3 = (√289)3
    = (17)3 = 4913