The school library newly bought 650 story books, 200 science and technology books, and 150 comic books. What percentage of the total number of science and technology books?
学校图书馆新买故事书650本，科技书200本，连环画150本，科技书占总数的百分之几？
<gadget id="calculator">650 + 200 + 150</gadget>
<output>1_000</output>

<gadget id="calculator">200 / 1_000</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>