A factory sold 350 parts on the first day. It is known that the ratio of sold to unsold is 7:4, how much is unsold?
某工场售出零件，第一天已售350个．已知已售的与未售的比是7：4，未售的是多少？
<gadget id="calculator">350 * 4</gadget>
<output>1_400</output>

<gadget id="calculator">1_400 / 7</gadget>
<output>200</output>

<result>200</result>