There are 45 animal specimens in the exhibition hall. The number of plant specimens is more than that of animal specimens (1/5), and the number of ore specimens is more than that of plant specimens (7/9). How many ore specimens are there?
展览馆有动物标本45件．植物标本的件数比动物标本多(1/5)，矿石标本的件数是植物标本的(7/9)．矿石标本有多少件？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 + (1/5)</gadget>
<output>6/5 = around 1.2</output>

<gadget id="calculator">7 / 9</gadget>
<output>7/9 = around 0.777778</output>

<gadget id="calculator">45 * (6/5) * (7/9)</gadget>
<output>42</output>

<result>42</result>