The crane can lift 2 tons of goods at a time. How many tons of goods can be lifted in total if it is lifted 15 times like this?
吊车一次能吊2吨的货物．照这样吊15次，一共能吊货物多少吨．
<gadget id="calculator">2 * 15</gadget>
<output>30</output>

<result>30</result>