The school bought 3 boxes of apples, each box has 2 layers, and each layer has 15 apples. How many apples are there in total?
学校买来3箱苹果，每箱2层，每层15个，一共有苹果多少个？
<gadget id="calculator">15 * 2 * 3</gadget>
<output>90</output>

<result>90</result>