The lifespan of sea lions is about 30 years, the lifespan of seals is 2/3 that of sea lions, and the lifespan of walruses is twice that of seals. What is the approximate lifespan of a walrus?
海狮的寿命大约是30年，海豹的寿命是海狮的(2/3)，海象的寿命是海豹的2倍．海象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">30 * (2/3) * 2</gadget>
<output>40</output>

<result>40</result>