Xinfeng TV Factory has produced 2,400 TV sets, which is less than the original plan (1/4). How many TV sets must be produced in order to produce 15% more than planned?
新风电视机厂，已生产电视机2400台，比原计划少(1/4)．为使产量超过计划15%，还要生产电视机多少台？
<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">2_400 / (3/4)</gadget>
<output>3_200</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 + (3/20)</gadget>
<output>23/20 = around 1.15</output>

<gadget id="calculator">3_200 * (23/20)</gadget>
<output>3_680</output>

<gadget id="calculator">3_680 - 2_400</gadget>
<output>1_280</output>

<result>1_280</result>