The school bought some desks and chairs, 108 sets were bought for the first time, and 15 sets were 3 times more than the first time, how many sets were bought for the second time?
学校购买了一些课桌椅，第一次买了108套，第二次买的比第一次的3倍还多15套，第二次买了多少套？
<gadget id="calculator">108 * 3</gadget>
<output>324</output>

<gadget id="calculator">324 + 15</gadget>
<output>339</output>

<result>339</result>