The school held a 100-meter race. Xiaobing took 17 seconds. Xiaoqiang was 2 seconds faster than Xiaobing. How many seconds did Xiaoqiang take?
学校举行100米跑比赛，小兵用了17秒，小强比小兵快2秒，小强用了多少秒？
<gadget id="calculator">17 - 2</gadget>
<output>15</output>

<result>15</result>