A garment factory produces a batch of school uniforms, and the ratio of the number of sets completed in the first 10 days to the total number of sets of this batch of school uniforms is 1:3. If 320 sets are produced again, just 40% of this batch of school uniforms can be completed. How many sets of school uniforms are there in total?
服装厂生产一批校服，前10天完成的套数与这批校服总套数的比是1：3．如果再生产320套，正好可以完成这批校服的40%．这批校服共有多少套？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) - (1/3)</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">320 / (1/15)</gadget>
<output>4_800</output>

<result>4_800</result>