How much is it to combine 90/6=15 and 600/15=40 into one comprehensive formula.
把90/6=15，600/15=40，合并成一道综合算式是多少．
<gadget id="calculator">90 / 6</gadget>
<output>15</output>

<gadget id="calculator">600 / 15</gadget>
<output>40</output>

<result>40</result>