Answer:
40%
Step-by-step explanation:
We would use an example
assume the price of the radio is 100
After the initial price reduction, it would be worth (100 - 20%) 80% of the price
0.8 x 100 = 80
After second price reduction it would be worth (100 - 25% ) 75% of the price
0.75 x 80 = 60
Price change = (new price after all the discounts / original price) - 1
(60/100) - 1 = -0.4
