Wang Min’s family used 1/5 of their total income in the first ten days of August, used the same amount in the middle and early days of August, and spent 3/10 of their total income in the second ten days of August. What fraction of Wang Min’s total income was left in August ?
王敏家八月份上旬用去总收入的(1/5)，中旬和上旬用去的同样多，下旬又用去总收入的(3/10)，王敏家八月份还剩下总收入的几分之几？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">(1/5) + (1/5) + (3/10)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>