Fuwa is the mascot of the 2008 Beijing Olympic Games. The gift shop sold 873 sets of Fuwa in the first half of September, 78 more than the original plan. How many sets did you plan to sell on average per day?
福娃是2008年北京奥运的吉祥物，礼品店九月份前半月卖了873套福娃，比原计划多卖了78套．原计划平均每天卖多少套？
<gadget id="calculator">873 - 78</gadget>
<output>795</output>

<gadget id="calculator">795 / 15</gadget>
<output>53</output>

<result>53</result>