###Human: There are 10 books on the table. Two-fifths of them are reading books and three-tenths of them are math books. There is one fewer science book than math books and the rest are history books. How many history books are there?, ### Assistant: Out of the 10 books, 10 x 2/5 = 4 are reading books.
While 10 x 3/10 = 3 are math books.
There are 3 - 1 = 2 science books.
So, the total number of reading, math, and science books is 4 + 3 + 2 = 9.
Thus, there is only 10 - 9 = 1 history book. 
 So the answer is :  1