A total of 180 trees were planted in the two groups. Group A planted 3 rows and Group B also planted 3 rows. How many trees were planted in each row on average?
两个组一共栽180棵树，甲组栽3行，乙组也栽3行，平均每行栽多少棵树？
<gadget id="calculator">3 + 3</gadget>
<output>6</output>

<gadget id="calculator">180 / 6</gadget>
<output>30</output>

<result>30</result>