The lifespan of a walrus is about 40 years, that of a sea lion is that of a walrus (2/3), and that of a seal is that of a sea lion (3/4). What is the approximate lifespan of a seal?
海象的寿命大约是40年，海狮的寿命是海象的(2/3)，海豹的寿命是海狮的(3/4)．海豹的寿命大约是多少年？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">40 * (2/3) * (3/4)</gadget>
<output>20</output>

<result>20</result>