5: The former term of 11 is increased by 15, in order to keep the ratio unchanged, how much should the latter term be increased.
5：11的前项增加15，为了使比值不变，后项要增加多少．
<gadget id="calculator">5 + 15</gadget>
<output>20</output>

<gadget id="calculator">20 / 5</gadget>
<output>4</output>

<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<gadget id="calculator">44 - 11</gadget>
<output>33</output>

<result>33</result>