Two classes in the fifth grade participated in the afforestation activity at the same time. The first class planted 15 more trees than the second class, just equivalent to (1/3) of the second class. How many trees did the second class plant?
五年级两个班同时参加植树造林活动，一班比二班多植树15棵，正好相当于二班的(1/3)，二班植树多少棵？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">15 / (1/3)</gadget>
<output>45</output>

<result>45</result>