Question

the weight of a 12 books is 9 kg what is the weight of 40 such books? ​

Answer 1

Question

The weight of 12 books is 9kg. What is the weight of 40 such books?

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Answer

Weight of 12 books ⇒ 9kg

Weight of 1 book ⇒ $\sf \frac{9}{12}$

$\sf \frac{3}{4} kg$

Weight of 40 books ⇒ $\sf \frac{3}{4}\times 40$

$\sf \frac{3}{4\div 4 }\times 40\div 4$

$\sf 3\times 10 = 30 kg$

∴If the weight of 12 books is 9kg then the weight of 40 such books would be 30kg.

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Additional Information

Unitary Method is finding the value of one thing and using this value to find the value of the required number of things.

There are two types of unitary methods.

• Direct Variation  
• Inverse Variation

Unitary Method is used in evaluating the price of things, time is taken by something in an hour, business to calculate profit or loss, etc.

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