The lifespan of a walrus is about 40 years, that of a sea lion is that of a walrus (3/4), and that of a sea lion is that of a seal (3/2). What is the lifespan of a seal.
海象的寿命大约是40年，海狮的寿命是海象的(3/4)，海狮的寿命是海豹的(3/2)．海豹的寿命是多少年．
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">3 / 2</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">(3/4) / (3/2)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 * (1/2)</gadget>
<output>20</output>

<result>20</result>