A cell phone originally priced at $120. The store owner gives a discount and the cell phone is now priced at $90. What is the percentage discount for the cost of the cell phone?

The answer to your question is 25%

Step-by-step explanation:

Data

Original price = $120

Price after discount = $90

Discount = ?

Process

1.- Consider that the original price is the 100%  and use a rule of three to find the percent of discount

                           $120 100%

                             $90 x

                             x = (90 x 100) / 120

                             x = 9000 / 120

                             x = 75%

2.- Calculate the percent of discount

$90 represents 75% of the original price, then,

       Percent of discount = 100 -75

                                         = 25 %              

{3 + i, 3 - i, 3, -1}

step-by-step explanation: