# What is the percent of increase from 50 to 90?

Mar 7, 2017

See the entire solution process and result below:

#### Explanation:

The formula for calculating the percentage or rate of change between two values is:

$p = \frac{N - O}{O} \cdot 100$

Where:

$p$ is the percent change - what we are solving for in this problem
$N$ is the New Value - 90 for this problem
$O$ is the Old Value - 50 for this problem

Substituting and solving for $p$ gives:

$p = \frac{90 - 50}{50} \cdot 100$

$p = \frac{40}{50} \cdot 100$

$p = \frac{4000}{50}$

$p = 80$

There was an 80% increase.