Three number are in the ratio 1:2:3 . The sum of their cubes is 79092 . Find the numbers


Given: Three numbers are in the ratio $=1:2:3$ and the sum of their cubes$=79092$.

To Find: To find all the three numbers.

Solution:

Let, The first number be $x$.

The second number be $2x$.

The third number be $3x$.

According to the question,

The sum of their cubes is $79092$.

$\Rightarrow x^3+( 2x)^3+( 3x)^3=79092$

$\Rightarrow x^3+8x^3+27x^3=79092$

$\Rightarrow 36x^3=79092$

$\Rightarrow x^3=\frac{79092}{36}$

$\Rightarrow x^3=2197$

$\Rightarrow x=\sqrt[3]{2197}$

$\Rightarrow x=\sqrt[3]{13\times13\times13}$

$\Rightarrow x=13$

Therefore, The first number $=x=1\times13=13$

The second number$=2x=2\times13=26$

The third number$=3x=3\times13=39$

Hence, the three numbers are $13,\ 36$ and $39$.

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Updated on: 10-Oct-2022

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