There are about 6 billion people in the world, only (2/5) people have sufficient fresh water security. How many billion people in the world do not have adequate fresh water security?
全世界约有60亿人，只有(2/5)的人有充足的淡水保障．全世界没有充足淡水保障的人有多少亿？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">60 * (3/5)</gadget>
<output>36</output>

<result>36</result>