Question

A sofa regularly sells for $790. The sale price is $624.10. How do you find the percent decrease of the sale price from the regular price?

Answer 1

`21%` decrease in price.

Explanation:

To calculate the percent change in any situation:
increase, decrease, profit, mark-up, discount, loss, growth, decline, etc..

Use the method:

`% " change " = "amount of change"/"original amount" xx100%`

The price of the sofa changed from `$790 " to " $624.10`

This is an amount of `$165.90`

`165.90/790 xx 100%`

=`21%` decrease in price

Answer 2

There was a -21% change or a 21% decrease of the sale price from the regular price.

Explanation:

The formula for calculating the percentage change of something is `p = (N - O)/O * 100` where `p` is the percentage change, `N` is the new value and `O` is the old value.

In this problem we are provided the old value of $790 and the new value of $624.10 which we can substitute into the formula to calculate the percentage change:

`p = (624.10 - 790)/790 * 100`

`p = -165.9/790*100`

`p = -16590/790`

`p = -21`