In order to cope with the financial crisis, a city increased investment to revitalize the economy. The total investment in the first quarter of this year was 2 billion yuan, an increase of 60% over the same period last year. How much was the total investment in the same period last year?
某市为应对金融危机，加大投资力度振兴经济，今年一季度投资总额为20亿元人民币，比去年同期增加60%，去年同期投资总额多少亿元？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 + (3/5)</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">20 / (8/5)</gadget>
<output>25/2 = around 12.5</output>

<result>25/2 = around 12.5</result>