This year, the number of buildings sold by Yongan Real Estate Company is on the rise. The ratio of the number of buildings sold in the first, second and third quarters is 3:4:5. 200 units were sold in the second quarter, how many more units were sold in the third quarter than in the first quarter?
今年，永安房产公司楼房销售数量呈上升趋势，一、二、三季度楼房销售数量之比是3：4：5．第二季度卖出200套，第三季度比第一季度多卖出多少套？
<gadget id="calculator">200 / 4</gadget>
<output>50</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">50 * 2</gadget>
<output>100</output>

<result>100</result>