A road is 90 meters long. On both sides of the road, a pine tree is planted every 6 meters from one end (both ends are planted), and a poplar tree is planted every 10 meters. Plant poplars. How many pine trees and poplars are there on this road?
一条公路长90米，在这条公路的两边从一端起每隔6米栽一棵松树(两端都栽)，再每隔10米栽一棵杨树，已栽上松树的地方就不再栽杨树，这条公路上松树和杨树一共有多少棵？
<gadget id="calculator">90 / 6</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<gadget id="calculator">90 / 10</gadget>
<output>9</output>

<gadget id="calculator">9 - 1</gadget>
<output>8</output>

<gadget id="calculator">8 - 4</gadget>
<output>4</output>

<gadget id="calculator">16 + 4</gadget>
<output>20</output>

<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<result>40</result>