The supermarket shipped 30 boxes of pure milk and 42 boxes of walnut milk. The price of the two kinds of milk is the same, 48 yuan per box. How much does the supermarket pay?
超市运来30箱纯牛奶和42箱核桃奶，两种奶的价格相同，每箱48元．超市要付多少元？
<gadget id="calculator">30 + 42</gadget>
<output>72</output>

<gadget id="calculator">72 * 48</gadget>
<output>3_456</output>

<result>3_456</result>