A table tennis match is going on in a gymnasium. Xiao Ming has a look at the scene of the match. There are a total of 50 players playing on 15 tables, which are divided into singles and doubles. How many people are playing singles?
某体育馆内正在进行乒乓球比赛，小明看了一下比赛现场的情况，一共有50人在15张球桌上比赛，分成单打和双打两项，有多少人在进行单打呢？
<gadget id="calculator">2 * 15</gadget>
<output>30</output>

<gadget id="calculator">50 - 30</gadget>
<output>20</output>

<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<result>10</result>