18 is 45% of what ?

Apr 20, 2018

$40$

Explanation:

$\frac{18}{40}$ will give you $0.45$, which is equal to 45%.

How to solve it:

1. $\text{ } 18 = 0.45 x$

2. $\text{ } \frac{18}{0.45} = x$

3. $\text{ } 40 = x$

Apr 20, 2018

$40$

Explanation:

The proportion I like to use with these types of problems goes like:

$\text{percent"/100 = "part"/"whole}$

Part/whole can also be written as "is/of"

So in this case:

• The part (is) is $18$
• The whole (of) is unknown to us - let's say $x$
• The percent (%) is $45$

Now:

$\frac{45}{100} = \frac{18}{x}$

We can cross multiply to get:

$45 x = 1800$

$x = 40$

Hope this helps!

Apr 20, 2018

$18$ is 45% of $40$.

Explanation:

Let $x$ represent the unknown number.

45%=45/100=0.45

$0.45 x = 18$

Divide both sides by $0.45$.

$x = \frac{18}{0.45}$

$x = 40$

Check.

$0.45 \left(40\right) = 18$

$18$ is 45% of $40$.