A computer salesperson said she would drop the price of a computer by $120, which was a 15% discount. what was the original selling price of the computer?

It would be $128 120 x's. 15 is 18 so 120+18 is 128

It was dropped by $120 which was a 15% discount.

Let the original price be x.

15% of x = $120

(15/100) x = 120

0.15x = 120

x = 120 / 0.15

x = 800

Hence the original price was $800.