Surds and Indices


  1. 812.5 x 94.5 ÷ 34.8 = 9?











  1. View Hint View Answer Discuss in Forum

    812.5 X 94.5 ÷ 34.8 = 9?

    Apply the law of Fractional Exponents and Laws of Exponents
    (am)n = am x n
    (am) x (an) = am + n
    am ÷ an = am ? n
    and if pX = pY then X will be equal to Y. means X = Y;

    Correct Option: A

    812.5 X 94.5 ÷ 34.8 = 9?
    ⇒ 812.5 x 94.5 ÷ 34.8 = 9?
    Apply the law of Fractional Exponents and Laws of Exponents
    (am)n = am x n ----------------1
    (am) x (an) = am + n-------------2
    am ÷ an = am ? n----------------3
    and if pX = pY then X will be equal to Y. means X = Y;----------------4

    Apply Law 1
    ⇒ (92)2.5 x 94.5 ÷ 32 x 2.4 = 9?
    ⇒ 95 x 94.5 ÷ 92.4 = 9?
    Apply law 2 and 3,
    ⇒ 9(5 + 4.5 - 2.4) = 9?
    ⇒ 9? = 97.1
    Apply the Law 4
    ? = 7.1


  1. ( 42 x 229 ) ÷ ( 9261)1/3 = ?











  1. View Hint View Answer Discuss in Forum

    Given that, (42 x 229) ÷ (9261)1/3 = ?
    As we know that (9621)1/3 = (21 x 21 x 21)1/3 = 213x1/3

    Solve the equation by using the Algebra Law.

    Correct Option: D

    Given that, (42 x 229) ÷ (9261)1/3 = ?
    As we know that (9621)1/3 = (21 x 21 x 21)1/3 = 213x1/3
    ∴ 42 x 229 ÷ (213 x )1/3 = ?
    ∴ 42 x 229 ÷ 21 = ?
    ∴ 42 x 229 x 1/ 21 = ?
    ∴ 2 x 229 = ?
    ? = 2 x 229
    ? = 458



  1. If 2p + 3q = 17 and 2p + 2 - 3q + 1 = 5, then, find the value of p and q ?









  1. View Hint View Answer Discuss in Forum

    Given equation is
    2p + 3q = 17
    2p + 2 - 3q + 1 = 5

    Apply the law of Fractional Exponents and Laws of Exponents
    (am) x (an) = am + n
    a-m = 1/am
    p0 = 1
    and if pX = pY then X will be equal to Y. means X = Y;
    (am)n = am x n
    (am) x (an) = am + n
    am ÷ an = am ? n
    Or
    am/an = am ? n

    Correct Option: C

    Apply the law of Fractional Exponents and Laws of Exponents
    (am) x (an) = am + n
    a-m = 1/am
    p0 = 1
    and if pX = pY then X will be equal to Y. means X = Y;
    (am)n = am x n
    (am) x (an) = am + n
    am ÷ an = am ? n
    Or
    am/an = am ? n

    Given equation is
    2p + 3q = 17 ----------------(i)
    2p + 2 - 3q + 1 = 5
    ⇒ 2p x 22 - 3q x 3 = 5
    ⇒ 2p x 4 - 3q x 3 = 5
    ⇒ 4 x 2p - 3 x 3q = 5---------------(ii)
    On multiplying Eq. (i) by 3 and adding it, with Eq. (ii), we get

    3 x 2p + 3 x 3q = 51
    4 x 2p - 3 x 3q = 5
    _____________________________
    7 x 2p = 56

    ⇒ 7 x 2p = 7 x 8
    ⇒ 2p = 8
    ⇒ 2p = 23
    p = 3

    On substituting the value of p in Eq. (i) . we get
    23 + 3q = 17
    ⇒ 8 + 3q = 17
    ⇒ 3q = 17 - 8
    ⇒ 3q = 9
    ⇒ 3q = 32
    q = 2


  1. LM is surd of order ........, where M is a rational number; L is a positive integer and LM is irrational.









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    L3 = M1/L = Surd of Lth order.

    Correct Option: A

    L3 = M1/L = Surd of Lth order.



  1. If 289 = 17x/5 , then x = ?











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    Given that , 289 = 17x/5
    Use the formula if a x = a y then x = y will be true.

    Correct Option: C

    Given that , 289 = 17x/5
    Use the formula if ax = a y then x = y will be true.
    ⇒ 171/2 = 17x/5
    ⇒ x /5 = 1/2
    ⇒ x = 10 .