Replace $ \square $ in each of the following by the correct number:
(a) $ \frac{2}{7}=\frac{8}{\square} $
(b) $ \frac{5}{8}=\frac{10}{\square} $
(c) $ \frac{3}{5}=\frac{\square}{20} $
(d) $ \frac{45}{60}=\frac{15}{\square} $
(e) $ \frac{18}{24}=\frac{\square}{4} $

To do:

We have to replace \( \square \) by the correct numbers.

Solution:

(a) Let $x$ be the number in the square.

Therefore,

$\frac{2}{7}=\frac{8}{x}$

On cross multiplication, we get,

$2\times x=7\times8$

$x=\frac{7\times8}{2}$

$x=7\times4$

$x=28$

The required number is 28.

(b) Let $x$ be the number in the square.

Therefore,

$\frac{5}{8}=\frac{10}{x}$

On cross multiplication, we get,

$5\times x=10\times8$

$x=\frac{10\times8}{5}$

$x=2\times8$

$x=16$

The required number is 16. 

(c) Let $x$ be the number in the square.

Therefore,

$\frac{3}{5}=\frac{x}{20}$

On cross multiplication, we get,

$3\times 20=x\times5$

$x=\frac{3\times20}{5}$

$x=3\times4$

$x=12$

The required number is 12. 

(d) Let $x$ be the number in the square.

Therefore,

$\frac{45}{60}=\frac{15}{x}$

On cross multiplication, we get,

$45\times x=15\times60$

$x=\frac{15\times60}{45}$

$x=\frac{60}{3}$

$x=20$

The required number is 20. 

(e) Let $x$ be the number in the square.

Therefore,

$\frac{18}{24}=\frac{x}{4}$

On cross multiplication, we get,

$18\times 4=x \times24$

$x=\frac{18\times4}{24}$

$x=\frac{18}{6}$

$x=3$

The required number is 3. 

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Updated on: 10-Oct-2022

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