The school cafeteria bought a batch of flour, used it for the first time (1/5), and used 40 kg for the second time. At this time, the weight ratio of the used flour to the remaining flour was 3:2. How much flour was bought back in the cafeteria? kilogram?
学校食堂买回一批面粉，第一次用去(1/5)，第二次用40千克，这时用去的与剩下的粉重量的比是3：2，食堂共买回面粉多少千克？
<gadget id="calculator">3 + 2</gadget>
<output>5</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/5) - (1/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / (2/5)</gadget>
<output>100</output>

<result>100</result>