Xincheng Furniture City has a total of 150 double beds and single beds. It is known that the ratio of double beds to single beds is 3:2. How many double beds are more than single beds?
新城家具城有双人床和单人床共150张，已知双人床与单人床的数量比是3：2，双人床比单人床多多少张？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">150 / 5</gadget>
<output>30</output>

<gadget id="calculator">30 * 3</gadget>
<output>90</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">90 - 60</gadget>
<output>30</output>

<result>30</result>