Tag: composition of ratios

Questions Related to composition of ratios

Multiple choice composition of ratios types of ratios ratio and proportions ratio and proportion maths

If $a : b = 1 : 1$ and $b : c = 81 : 24$, then the subtriplicate ratio of $a : c$ is ____

  1. $1 : 24$

  2. $3 : 2$

  3. $2 : 3$

  4. $24 : 81$

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

$a : b = 1 : 1$ and $b : c = 81 : 24$
$\therefore \dfrac {a}{b} \times \dfrac {b}{c} = \dfrac {1}{1} \times \dfrac {81}{24} = \dfrac {27}{8}$
$\therefore a : c = 27 : 8$
$\therefore$ The subtriplicate ratio of $27 : 8$ is $\sqrt [3]{27} : \sqrt [3]{8} = 3 : 2$

Multiple choice composition of ratios types of ratios ratio and proportions ratio and proportion maths

The subtriplicate ratio of $\sqrt {x} : \sqrt {y}$ is ____

  1. $x^{\frac {1}{9}} : y^{\frac {1}{9}}$

  2. $\sqrt {y} : \sqrt {x}$

  3. $x^{\frac {1}{3}} : y^{\frac {1}{6}}$

  4. $x^{\frac {1}{6}} : y^{\frac {1}{6}}$

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The subtriplicate ratio of $a : b$ is $\sqrt [3]{a} : \sqrt [3]{b}$
$\therefore$ The subtriplicate ratio of $\sqrt {x} : \sqrt {y} = x^{\cfrac {1}{2}} : y^{\frac {1}{2}}$ is $(x^{\cfrac {1}{2}})^{\cfrac {1}{3}} : (y^{\cfrac {1}{2}})^{\cfrac {1}{3}}$
$= x^{\cfrac {1}{6}} : y^{\cfrac {1}{6}}$

Multiple choice composition of ratios types of ratios ratio and proportions ratio and proportion maths

The sub-triplicate ratio of $3 : 81$ is ____

  1. $81 : 3$

  2. $\sqrt {3} : 3$

  3. $1 : 3$

  4. $\sqrt {3} : 9$

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The subtriplicate ratio of $a : b$ is $\sqrt [3]{a} : \sqrt [3]{b}$
Now, $3 : 81 = \dfrac {3}{81} = \dfrac {1}{27} = 1 : 27$
$\therefore$ The subtriplicate ratio of $1 : 27$ is $\sqrt [3]{1} : \sqrt [3]{27} = 1 : 3$