The store shipped (13/15) tons of vegetables, cucumbers 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 did potatoes account for?
商店运来(13/15)吨蔬菜，黄瓜占总数的(4/15)，西红柿占总数的(2/5)，其它的是土豆，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">1 - (4/15) - (2/5)</gadget>
<output>1/3 = around 0.333333</output>

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