Question

A cup of broth can have $870$$milligrams$ of salt, which is $30\%$ of the recommended daily allowance.

What is the recommended daily amount?

Answer 1

Find the recommended daily amount:

Amount of salt in a cup of broth$=870\mathrm{milligrams}$

According to the question,

The amount is $30\%$ of the recommended daily amount.

Let the daily amount is $x$.

Then $30\%$ of $x$ can be written as $\frac{30}{100}\left(x\right)$

Now, $30\%$ of $x$ can be written as:

$$\begin{gathered} \frac{30}{100}\left(x\right)=870 \\ \Rightarrow 30x=870\left(100\right) \\ \therefore 30x=87000 \end{gathered}$$

Dividing both sides by $30$.

$$\begin{gathered} \frac{30x}{30}=\frac{87000}{30} \\ \therefore x=2900 \end{gathered}$$

Hence, the recommended daily amount is $2900$ $milligrams$.