Central primary school students watered 50 trees in the third grade, 35 more in the fourth grade than in the third grade, twice as many in the fifth grade as in the fourth grade, how many more trees in the fifth grade than in the third grade?
中心小学学生抬水浇树，三年级浇了50棵，四年级比三年级多浇35棵，五年级浇的棵数是四年级的2倍，五年级比三年级多浇多少棵树？
<gadget id="calculator">50 + 35</gadget>
<output>85</output>

<gadget id="calculator">85 * 2</gadget>
<output>170</output>

<gadget id="calculator">170 - 50</gadget>
<output>120</output>

<result>120</result>