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4 years ago

Four brothers and their sister have the average age 7. Four brothers have the average age 6. How old is the sister?

Mathematics

1 answer:

AnnyKZ [126]4 years ago

4 0

Answer:

11 years old

Step-by-step explanation:

If four brothers have the average age 6, then the sum of their ages is

$4\cdot 6=24$

years.

Let x years be the age of sister. If four brothers and their sister have the average age 7, then

$\dfrac{24+x}{5}=7.$

Multiply this equation by 5:

$24+x=35\Rightarrow x=35-24=11.$

The sister is 11 years old.

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The triangular-shaped bases of a prism are 24 cm in length and have a height of 35 cm. Each side is 37 cm. The height of the pri

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Step-by-step explanation:

Given in question as :

For a Triangular base prism ,

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