The students carried water to water the trees. The third grade watered 50 trees, the fourth grade watered 35 more trees than the third grade, the fifth grade watered twice as many trees as the fourth grade, how many trees in the fifth grade? (column synthesis)
同学们抬水浇树，三年级浇了50棵，四年级比三年级多浇35棵，五年级浇的棵数等于四年级的2倍，五年级浇多少棵？(列综合式)
<gadget id="calculator">50 + 35</gadget>
<output>85</output>

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

<result>170</result>