Question

After an increase of 20% a number becomes 540 find the original number

Answer 1

450

Explanation:

Let the number be represented by x. "an increase of 20%" can be represented as:

100% x + 20% x ⇒ 120% x

We also know that 540 is equivalent to 120% x. We can use this information set up a simple equation.

540 = 120% x

Now, we just have to isolate the variable. Percentages can also be represented as fractions.

`\text{fraction}\Rightarrow\frac{\text{percentage number}}{100}`

Using this information, we can convert 120% x into...

540 = 120/100 × x

We can simplify the fraction using the GCF (greatest common factor) of the two numbers.

540 = 6/5 × x

Multiply both sides by 5

2700 = 6x

Divide both sides by 6

x = 450

The original number was 450.