i have a word problem can someone please help

[acidrazzor]

i have 18,000 apples but i lose 0.5% every day. how many apples do i lose after the first day. i am not sure if i lose half of them or if i only lose 90 per day can someone please help. i thought it was 18,000 * 0.5=9,000 but someone told me i needed to do 18,000 - 0.5%= 17910 so i losed 90 apples. which one is the right way to do this problem or is there another way to do it.