Question

Given,$\dfrac{9}{{10}}$ of your blood is water: what $\% $ of your blood is not water.

Answer 1

Hint: In order to find the percentage of your blood that is not water, first find the fraction of the blood that is not water as the value is given in fraction, then multiply the fraction value with $100$ as we know that percent means per hundred.

Complete answer:
We are given the statement that $\dfrac{9}{{10}}$ of your blood is water.
Since, we know that a total fraction is always one. Which means that the sum of the fraction of the blood that is water and the fraction of the blood that is not water is one, as they are proper fractions.
Let, the fraction of blood that is not water be “x”.
So, numerically it can be written as:
$\left( {{\text{blood that is water}}} \right) + \left( {{\text{blood that is not water}}} \right) = 1$
Substituting the values in the above equation, we get:
$ \Rightarrow \dfrac{9}{{10}} + x = 1$
Subtracting both sides by $\dfrac{9}{{10}}$, we get:
$ \Rightarrow \dfrac{9}{{10}} + x - \dfrac{9}{{10}} = 1 - \dfrac{9}{{10}}$
$ \Rightarrow x = 1 - \dfrac{9}{{10}}$
Multiplying and dividing “x” by $10$ in order to have a common denominator, and so we get:
$ \Rightarrow x = \dfrac{{10}}{{10}} - \dfrac{9}{{10}}$
Taking the denominator common and subtracting, and we get:
$ \Rightarrow x = \dfrac{{10 - 9}}{{10}}$
$ \Rightarrow x = \dfrac{1}{{10}}$
Therefore, the fraction of blood that is not water is $\dfrac{1}{{10}}$.
To get the percentage of the fraction of blood that is not water multiplying the fraction by $100$
Numerically written as:
(Percentage) $\% $ of fraction of blood that is not water $ = \dfrac{1}{{10}} \times 100\% $
On solving, we get:
(Percentage) $\% $ of fraction of blood that is not water $ = 10\% $.
Therefore, $10\% $ of your blood is not water, if $\dfrac{9}{{10}}$ of your blood is water.
Therefore, Option A is correct.

Note:
1.We can convert the fraction into decimal if needed then multiply by $100$ to get the percentage.
2.Using the same steps, a percentage can be converted into a fraction.
3.A total unit of a fraction is always considered to be one.
4.A proper fraction is a fraction whose numerator is always less than the denominator.