When buying disaster relief stamps, Xiao Ming bought 5 sets and Xiao Hu bought 8 sets. It is known that Xiaohu paid 12 yuan more than Xiaoming. How much is each set of disaster relief stamps?
买赈灾邮票，小明买了5套，小虎买了8套．已知小虎比小明多付12元钱．问赈灾邮票每套多少元？
<gadget id="calculator">8 - 5</gadget>
<output>3</output>

<gadget id="calculator">12 / 3</gadget>
<output>4</output>

<result>4</result>