(4/15) of a number is (3/5) of 60, what is this number?
一个数的(4/15)是60的(3/5)，这个数是多少．
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">4 / 15</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">(3/5) / (4/15)</gadget>
<output>9/4 = around 2.25</output>

<gadget id="calculator">60 * (9/4)</gadget>
<output>135</output>

<result>135</result>