Xiaolan and her father and mother go to the individual barber shop for a haircut. Xiaolan needs 30 minutes, her father needs 20 minutes, and her mother needs 2 hours. What is the minimum total waiting time of the three people?
小兰和爸爸、妈妈去个体理发店理发，小兰需要30分钟，爸爸需要20分钟，妈妈需要2小时，三人等候时间的总和最少要多少分钟．
<gadget id="calculator">20 * 3</gadget>
<output>60</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">120 * 1</gadget>
<output>120</output>

<gadget id="calculator">60 + 60 + 120</gadget>
<output>240</output>

<result>240</result>