10/200 is equivalent to 5/100 which can be simplified to 1/20, meaning 1/20 of the apples have gone bad.
190 apples are still okay. in this equation 200 is 100% . if you find 10% of 200 it would be 20. now you have to find 5% which is half of 20 so 10. meaning now you have to find how many 20’s and 10’s go into 190. the answer is 9 20’s and 1 10. So now you add 9 10%’s together to get 90% and add 10 which is 5%, meaning the total of apples that were still good to eat would be 95%.
