There are 150 trees in the campus, among which (3/10) are pine trees and (1/5) are ginkgo trees. How many pine trees and ginkgo trees are there?
校园里有150棵树，其中(3/10)是松树，(1/5)是银杏树．松树、银杏树共有多少棵？
<gadget id="calculator">3 / 10</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/10) + (1/5)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">150 * (1/2)</gadget>
<output>75</output>

<result>75</result>