During the "June 1st" festival, my father and mother took Xiaoming to the park and bought tickets for 10.5 yuan. It is known that the price of one adult ticket is equal to the price of three children's tickets. How much is an adult ticket?
"六一"节时，爸爸、妈妈带小明游公园，买门票共用去10.5元，已知一张大人票价与三张小孩票价相等．一张大人票多少元？
<gadget id="calculator">3 * 2</gadget>
<output>6</output>

<gadget id="calculator">6 + 1</gadget>
<output>7</output>

<gadget id="calculator">10.5 / 7</gadget>
<output>1.5</output>

<gadget id="calculator">1.5 * 3</gadget>
<output>4.5</output>

<result>4.5</result>