Square root and cube root


  1. If √2n = 64, then the value of n is ?









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    2n = 64
    ⇒ 2n/2 = 26

    Correct Option: D

    2n = 64
    ⇒ 2n/2 = 26
    ⇒ n/2 = 6
    ⇒ n = 12


  1. If √6 = 2.55, then the value of √2/3 + 3 √3/2 is ?









  1. View Hint View Answer Discuss in Forum

    =√2/3 + 3√3/2
    = √2/√3 x √3/√3 + 3√3/√2 x √2/ √2
    = √6/3 + 3√6/2
    = (2.55 / 3) + [(3 x 2.55) / 2]

    Correct Option: D

    =√2/3 + 3√3/2
    = √2/√3 x √3/√3 + 3√3/√2 x √2/ √2
    = √6/3 + 3√6/2
    = (2.55 / 3) + [(3 x 2.55) / 2]
    = 2.55/3 + 7.65/2
    = (5.10 + 22.95)/6
    = 28.05/6
    = 4.675



  1. If √3 =1.732 and √2 = 1.414, the value of 1/(√3 + √2) is ?









  1. View Hint View Answer Discuss in Forum

    1/ (√3 + √2)
    = (√3 - √2) / [ 1/ (√3 - √2) x (√3 + √2)]
    = (√3 - √2) / (3 - 2)

    Correct Option: C

    1/ (√3 + √2)
    = (√3 - √2) / [ 1/ (√3 - √2) x (√3 + √2)]
    = (√3 - √2) / (3 - 2)
    = (1.7732 - 1.414) = 0.318


  1. (√32 + √48) / (√8 + √12) = ?









  1. View Hint View Answer Discuss in Forum

    (√32 + √48) / (√8 + √12)
    = (√16 x 2 + √16 x 3) / (√4 x 2 + √4 x 3)
    = (4√2 + 4√3) / (2√2 + 2√3)
    = 4(√2 + √3) / 2(√2 + √3 ) = 2

    Correct Option: B

    (√32 + √48) / (√8 + √12)
    = (√16 x 2 + √16 x 3) / (√4 x 2 + √4 x 3)
    = (4√2 + 4√3) / (2√2 + 2√3)
    = 4(√2 + √3) / 2(√2 + √3 ) = 2



  1. 176 + √2401 = ?









  1. View Hint View Answer Discuss in Forum

    176 + √2401
    = √176 + 49
    = √225 = 15

    Correct Option: B

    176 + √2401
    = √176 + 49
    = √225 = 15