Zhoushan Fishery Company has 150 tons of seafood to be shipped to other places. The first time it shipped 20% of the total, and the second time it shipped 1/2 of the total. How many tons of seafood are left?
舟山渔业公司有150吨海产品要运往外地，第一次运了总数的20%，第二次运了总数的(1/2)．还剩下多少吨海产品？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/5) - (1/2)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">150 * (3/10)</gadget>
<output>45</output>

<result>45</result>