A florist can make a profit of 2 yuan by selling a lily, and can make a profit of 1.5 yuan by selling a rose. The flower shop made a profit of 50 yuan after selling 30 lilies and roses yesterday. How many lilies did the florist sell? (solution by equation)
一个花店卖出一枝百合花可获利2元，卖出一枝玫瑰花可获利1.5元．花店昨天卖出百合花和玫瑰花共30枝后，获利50元．花店卖出百合花多少枝？(用方程解)
<gadget id="calculator">1.5 * 30</gadget>
<output>45</output>

<gadget id="calculator">50 - 45</gadget>
<output>5</output>

<gadget id="calculator">2 - 1.5</gadget>
<output>0.5</output>

<gadget id="calculator">5 / 0.5</gadget>
<output>10</output>

<result>10</result>