There are 52 books on the first floor of a bookshelf, and 95 books on the second and third floors. How many books are on each floor on average?
一个书架上第一层放书52本，第二层和第三层共放书95本，平均每层放书多少本？
<gadget id="calculator">52 + 95</gadget>
<output>147</output>

<gadget id="calculator">147 / 3</gadget>
<output>49</output>

<result>49</result>