Question

5 to 2 = __ to 4 and also 14 to 21 = __ to 15

Answer 1

1) Set up proportions for the ratios:

$\frac{5}{2} = \frac{x}{4}$

Cross multiply the fractions:

$2x = 20$

Divide both sides by 2 to get x by itself.

$x = 10$

5 to 2 is equal to 10 to 4.
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2) Set up proportions for the ratios:

$\frac{14}{21} = \frac{x}{15}$

Cross multiply the fractions:

$21x = 210$

Divide both sides by 21 to get x by itself:

$x = 10$

14 to 21 is equal to 10 to 15.
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OPTIONAL:
To make 2) easier to solve, simplify 14 to 21.

$\frac{14}{21} / \frac{7}{7} = \frac{2}{3}$

Then, continue with the problem as described above:

$\frac{2}{3} = \frac{x}{15}$

$3x = 30$

$x = 10$