Huai'an shopping mall held a New Year's Day sales promotion. On January 1st, the unit price of a certain brand of woolen sweaters in the afternoon was less than that in the morning (2/7), and the number of pieces sold in the morning was less than in the afternoon (3/5). It is known that this kind of sweater is sold for a total of 7800 yuan today. How much is the price in the morning?
淮安商场举行庆元旦促销活动，1月1日这一天，某种品牌的羊毛衫下午的单价比上午少(2/7)，上午售出的件数比下午少(3/5)．已知此种羊毛衫今天共售7800元．其中上午售价多少元？
<gadget id="calculator">14 + 25</gadget>
<output>39</output>

<gadget id="calculator">14 / 39</gadget>
<output>14/39 = around 0.358974</output>

<gadget id="calculator">7_800 * (14/39)</gadget>
<output>2_800</output>

<result>2_800</result>