What is the final price of a stereo originally costing $125 after a 20% discount?

To determine the final price of the stereo after applying a 20% discount to the original price of $125, it is essential to first calculate the amount of the discount.

The discount can be calculated by multiplying the original price by the discount rate: [

\text{Discount} = \text{Original Price} \times \text{Discount Rate} ] [ \text{Discount} = 125 \times 0.20 = 25 ]

Next, you subtract the discount from the original price to find the final price: [ \text{Final Price} = \text{Original Price} - \text{Discount} ] [ \text{Final Price} = 125 - 25 = 100 ]

This calculation shows that after a 20% discount, the final price of the stereo is indeed $100.