Uncle Zhang’s family planted 15 rows of pear trees, 17 rows of peach trees and 8 rows of apple trees. There are 17 rows of pear trees, 8 rows of peach trees, and 9 rows of apple trees. How many pear trees and peach trees are there in total? ? (List sorting conditions, then answer)
张大伯家种了15行梨树，17行桃树和8行苹果树，梨树每行17棵，桃树每行8棵，苹果树每行9棵，梨树和桃树一共有多少棵？(列表整理条件，再解答)
<gadget id="calculator">17 * 15</gadget>
<output>255</output>

<gadget id="calculator">8 * 17</gadget>
<output>136</output>

<gadget id="calculator">255 + 136</gadget>
<output>391</output>

<result>391</result>