Give the step-by-step reasoning process and then the final answer. There were 600 cookies in a box. Nicole ate 2/5 of the total number of cookies, while Eduardo ate 3/5 of the remaining amount. What percentage of the original cookies remained?
Nicole ate 2 / 5 of the total number of cookies, which is 2 / 5 * 600 = 240. The total number of cookies that remained in the box after Nicole ate 240 is 600 - 240 = 360. Eduardo then ate 3 / 5 of the remaining cookies, a total of 3 / 5 * 360 = 216 cookies. The total number of cookies that remained after Eduardo ate 216 is 360 - 216 = 144. The percentage of the cookies that remained out of the original amount is 144 / 600 * 100% = 24%.
The final answer: 24.