garment factory produces a batch of school uniforms. The ratio of the number of completed sets to the number of unfinished sets in the first 10 days is 1:3. If 180 sets are produced again, this batch of school uniforms can just be completed. How many sets of school uniforms are there in total?
服装厂生产一批校服，前10天完成的套数与未完成套数的比是1：3．如果再生产180套，正好可以完成这批校服．这批校服共有多少套？
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">180 / (3/4)</gadget>
<output>240</output>

<result>240</result>