The students watered 32 trees in the second grade, three times as many trees in the third grade, and 15 fewer trees in the fourth grade than in the second and third grades. How many trees did fourth grade water? (comprehensive answers)
同学们浇树，二年级浇了32棵，三年级浇的棵数是二年级的3倍，四年级浇的棵数比二、三年级的总数少15棵．四年级浇了多少棵树？(列综合式解答)
<gadget id="calculator">32 * 3</gadget>
<output>96</output>

<gadget id="calculator">32 - 15</gadget>
<output>17</output>

<gadget id="calculator">96 + 17</gadget>
<output>113</output>

<result>113</result>