If 40% of a number is 1.8, what is 60% of this number?
一个数的40%是1.8，那么这个数的60%是多少．
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1.8 / (2/5)</gadget>
<output>4.5</output>

<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4.5 * (3/5)</gadget>
<output>2.7</output>

<result>2.7</result>