During the year the students read 200 library books of those 2/5 were non-fiction if corner of the non-fiction books were books about nature what fractional part of the books were about nature

Answer 1

not sure what the corner has to do with things, but
2/5 of 200 = 80
so maybe you can determine what "corner" of 80 is.
Then divide that by 200 to get the fraction of the books you need.