Tag: maths

Questions Related to maths

The sub-duplicate ratio of $\dfrac {1}{25} : \dfrac {1}{64}$ is _____

  1. $\dfrac {1}{5} : \dfrac {1}{8}$

  2. $5 : 4$

  3. $\dfrac {1}{125} : \dfrac {1}{252}$

  4. $1 : 1$


Correct Option: A
Explanation:

The subduplicate ratio of $a : b$ is $\sqrt {a} : \sqrt {b}$
$\therefore$ The subduplicate ratio of $\dfrac {1}{25} : \dfrac {1}{64}$ is $\sqrt {\dfrac {1}{25}} : \sqrt {\dfrac {1}{64}} = \dfrac {1}{5} : \dfrac {1}{8}$

The triplicate ratio of $\sqrt [3]{b^{2}} : \sqrt [3]{a^{2}}$ is _____

  1. $b^{2} : a^{2}$

  2. $a : b$

  3. $b^{3} : a^{3}$

  4. $a^{2} : b^{2}$


Correct Option: A
Explanation:

The triplicate ratio of $a : b$ is $a^{3} : b^{3}$
$\therefore$ The triplicate ratio of $\sqrt [3]{b^{2}} : \sqrt [3]{a^{2}}$ is $(\sqrt [3]{b^{2}})^{3} : (\sqrt [3]{a^{2}})^{3} = b^{2} : a^{2}$.

The sub-duplicate ratio of $9 : 16$ is _____

  1. $3 : 4$

  2. $81 : 256$

  3. $4 : 3$

  4. $\sqrt {3} : \sqrt {4}$


Correct Option: A
Explanation:

The sub-duplicate ratio of $a : b$ is $\sqrt {a} : \sqrt {b}$.
$\therefore$ The subduplicate ratio of $9 : 16$ is $\sqrt {9} : \sqrt {16} = 3 : 4$

The triplicate ratio of $a^{2} : b^{2}$ is _____

  1. $\sqrt [3]{a^{2}} : \sqrt [3]{b^{2}}$

  2. $a^{3} : b^{3}$

  3. $a^{6} : b^{6}$

  4. $a^{9} : b^{9}$


Correct Option: C
Explanation:

The triplicate ratio of $a : b$ is $a^{3} : b^{3}$
$\therefore$ The triplicate ratio of $a^{2} : b^{2}$ is $(a^{2})^{3} : (b^{2})^{3} = a^{6} : b^{6}$.

The triplicate ratio of $ab^{\frac {2}{3}} : a^{\frac {2}{3}}b$ is _____

  1. $1 : 1$

  2. $ab : 1$

  3. $a^{3}b^{2} : a^{2}b^{3}$

  4. $a : b$


Correct Option: D
Explanation:

The triplicate ratio of $ab^{\frac {2}{3}} : a^{\frac {2}{3}} b$ is $(ab^{\frac {2}{3}})^{3} : (a^{\frac {2}{3}}b)^{3}$
$= a^{3} \cdot b^{2} : a^{2}b^{3}$
$a^{3}b^{2} : a^{2}b^{3} = \dfrac {a^{3}b^{2}}{a^{2}b^{3}} = \dfrac {a}{b}$

______ is the triplicate ratio of $\dfrac {x}{2} : \sqrt [3]{x}$

  1. $\dfrac {x^{3}}{8} : x^{3}$

  2. $8 : x$

  3. $x^{3} : 8$

  4. $x^{2} : 8$


Correct Option: D
Explanation:

The triplicate ratio of $a : b$ is $a^{3} : b^{3}$
$\therefore$ The triplicate ratio of $\dfrac {x}{2} : \sqrt [3]{x}$ is $\left (\dfrac {x}{2}\right )^{3} : \left (\sqrt [3]{x}\right )^{3} = \dfrac {x^{3}}{8} : x = \dfrac {x^{2}}{8}$
$\therefore x^{2} : 8$.

_____ is the subduplicate ratio of $49 : 169$

  1. $9 : 16$

  2. $7 : 13$

  3. $13 : 7$

  4. $169 : 49$


Correct Option: B
Explanation:

The subduplicate ratio of $a : b$ is $\sqrt {a} : \sqrt {b}$
$\therefore$ The subduplicate ratio of $49 : 169$ is $\sqrt {49} : \sqrt {169} = 7 : 13$

The subtriplicate ratio of $125y^{3} : 1000z^{6}$ is ____

  1. $5y : 10z^{3}$

  2. $5y : 10z^{2}$

  3. $1000z^{6} : 125y^{3}$

  4. $10^{3} : 5y$


Correct Option: B
Explanation:

The subtriplicate ratio of $a : b$ is $\sqrt [3]{a} : \sqrt [3]{b}$.
$\therefore$ The subtriplicate ratio of $125y^{3} : 1000z^{6}$ is $\sqrt [3]{125y^{3}} : \sqrt [3]{1000z^{6}} = 5y : 10z^{2}$.

The subtriplicate ratio of $8x^{3} : y^{3}$ is ____

  1. $2x : y$

  2. $4x : y$

  3. $8x : y$

  4. $y^{3} : 8x^{3}$


Correct Option: A
Explanation:

The subtriplicate ratio of $a : b$ is $\sqrt [3]{a} : \sqrt [3]{b}$.
$\therefore$ the subtriplicate ratio of $8x^{3} : y^{3}$ is $\sqrt [3]{8x^{3}} : \sqrt [3]{y^{3}} = 2x : y$

The subtriplicate ratio of $64m^{6} : 27n^{3}$ is ____

  1. $27n^{3} : 64 m^{6}$

  2. $4m : 3n$

  3. $4m^{2} : 3n$

  4. $4m^{3} : 3n$


Correct Option: C
Explanation:

The subtriplicate ratio of $a : b$ is $\sqrt [3]{a} : \sqrt [3]{b}$
$\therefore$ The subtriplicate ratio of $64 m^{6} : 27 n^{3}$ is $\sqrt [3]{64m^{6}} : \sqrt [3]{27n^{3}}$
$= 4m^{2} : 3n$