We calculate the discounts separately, first the 40% discount, the 40% of $800 is calculated like this:
(40%)(800) = (40/100)(800) = 320
So the first discount is $320, giving us a discounted price of:
800 - 320 = 480
Hence the discounted price with the first discount is $480
Then it is applied another 20%, so we repeat the process again with the new data:
(20%)(480) = (20/100)(480) = 96
Therefore the second discount is for $96, finally the price payed as final cost is what we had with the first discount $480 minus the second discount $96
480 - 96 = 384
The final cost is $384
