Southern Teachers of Elite Education: Solution: (1) Earnings per share is 3000× (13-9) ÷ (13× 6-9× 7) = 800 yuan;

Uncle Zhang and Uncle Li earned a total of 800×(7+6)= 10400 yuan in June.

(2) Science book 2 100×5/7= 1500, story book 2100-1500 = 600;

Later, there were 600÷2/9 = 2700 science and technology books.

So I later bought 2700- 1500= 1200 science and technology books.