The women's clothing store has several dresses, and the purchase price of each is 84 yuan. The store sells each dress at a price of 140 yuan. When half of the number of dresses and 15 pieces are sold, the cost is just recovered. How much profit will the store make after all these dresses are sold? (Solve using arithmetic method)
妇女服装店有连衣裙若干件，每件进价84元．商店以每件140元的价格出售，当售出连衣裙件数的一半零15件时，正好收回成本．问这些件连衣裙全部售出后，商店可盈利多少元？(用算术方法解答)
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">140 * (1/2)</gadget>
<output>70</output>

<gadget id="calculator">84 - 70</gadget>
<output>14</output>

<gadget id="calculator">15 / 14</gadget>
<output>15/14 = around 1.071429</output>

<gadget id="calculator">140 * (15/14)</gadget>
<output>150</output>

<gadget id="calculator">150 * (1/2)</gadget>
<output>75</output>

<gadget id="calculator">75 - 15</gadget>
<output>60</output>

<gadget id="calculator">140 * 60</gadget>
<output>8_400</output>

<result>8_400</result>