Answer :
let the no of non fiction books be x
so, no of fiction books = x+240
and no of picture books = x -190
total no of books = x+x+240+x-190 = 2630
or, x = 860 = no of non fiction books
no of fiction books = 860+240 =1100
no of picture books = 860-190 = 670
so, no of fiction books = x+240
and no of picture books = x -190
total no of books = x+x+240+x-190 = 2630
or, x = 860 = no of non fiction books
no of fiction books = 860+240 =1100
no of picture books = 860-190 = 670