A batch of cloth can be made into 60 sets of adult clothing or 90 sets of children's clothing. If adult clothing and 30 sets of children's clothing are made respectively, how many sets of children's clothing can be made from the remaining cloth?
一批布，可以做成人服装60套或做儿童服装90套，如果成人服装和儿童服装各做30套，余下的布还可以做儿童服装多少套？
<gadget id="calculator">1 / 90</gadget>
<output>1/90 = around 0.011111</output>

<gadget id="calculator">30 * (1/90)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 60</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">30 * (1/60)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/3) - (1/2)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) / (1/90)</gadget>
<output>15</output>

<result>15</result>