A batch of TV sets are shipped from the store, and 18 sets are sold. The ratio of the number of sets sold to the number of sets shipped is 3:7. How many TV sets were shipped in total?
商店运来一批电视机，卖出18台，卖出的台数与运来的台数的比是3：7．共运来电视机多少台？
<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">18 / (3/7)</gadget>
<output>42</output>

<result>42</result>