A bookshop had science and art books in the ratio of 2:5. By the end of the week, 20% of both type of books were sold and 2240 books were unsold. How many art books were there at the starting?
Choose the correct choice from the following answers.
A) 1355
B) 1350
C) 1450
D) 1600
E) 2000
science books sold = 2x × 0.2 = 0.4x   science books unsold = 2x – 0.4x = 1.6x   art books sold = 5x × 0.2 = x   art books unsold = 5x – x = 4x   total books unsold = 1.6x + 4x = 5.6x   5.6x 1.6  + 4= 
<gadget id="calculator">1.6  + 4</gadget>
<output>5.6</output>
5.6x   5.6x= 2240   x = 400   2x science = 800   and 5x art books = 2000   2000
<result>E</result>
A bookshop had science and art books in the ratio of 2:5. By the end of the week, 20% of both type of books were sold and 2240 books were unsold. How many art books were there at the starting?