 
 <translate> If she had 400 papers, the total number of documents she separated as invalid is 40 / 100 * 400 pages = 160 pages. The number of valid documents is 400 pages - 160 pages = 240 pages.
The final answer: 240. <ibo> Ọ bụrụ na o nwere akwụkwọ 400, ngụkọta nke akwụkwọ ndị o wepụrụ dị ka ndị na-abaghị uru bụ 40 / 100 * peeji 400 = peeji 160. Ọnụ ọgụgụ akwụkwọ ndị dị irè bụ peeji 400 - peeji 160 = peeji 240. Azịza ikpeazụ ya bụ: 240. 