60% of the number of boys is equal to the number of girls (9/10). There are 60 boys, how many girls are there?
男生人数的60%与女生人数(9/10)的相等，男生有60人，女生有多少人？
<gadget id="calculator">60 / 100</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">(3/5) / (9/10)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">60 * (2/3)</gadget>
<output>40</output>

<result>40</result>