certain unit bought a batch of flowers to beautify the environment, including 120 pots of azaleas, 20 pots more than twice the number of Begonias, how many pots are there of Begonias, and what is the correct list
某单位买来一批花卉美化环境，其中杜娟花120盆，比海棠花的2倍还多20盆，求海棠花有多少盆，正确的列式是多少
<gadget id="calculator">120 - 20</gadget>
<output>100</output>

<gadget id="calculator">100 / 2</gadget>
<output>50</output>

<result>50</result>