The school cafeteria bought a batch of vegetables, among which green beans accounted for (4/15) of the total, tomatoes accounted for (2/5) of the total, and the rest were potatoes. What percentage of the vegetables do potatoes make up?
学校食堂买来一批蔬菜，其中四季豆占总数的(4/15)，西红柿占总数的(2/5)，其他的是土豆．土豆占这批蔬菜的几分之几？
<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(4/15) + (2/5)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<result>1/3 = around 0.333333</result>