The fourth graders of the Arbor Day participated in the tree planting. There are 25 groups in total. Each group has 4 people who are responsible for digging holes and planting trees, and 2 people who are responsible for carrying water and watering trees. Each group needs to plant 5 trees. How many students participated in this event? Tree planting activity?
植树节四年级同学参加植树，一共有25个小组，每组有4人负责挖坑种树，2人负责抬水浇树，每组要种5棵树，一共有多少位同学参加了这次植树活动？
<gadget id="calculator">4 + 2</gadget>
<output>6</output>

<gadget id="calculator">6 * 25</gadget>
<output>150</output>

<result>150</result>