A ratio is 5:7, if the former term of the ratio is increased by 35, how much should the latter term be increased to keep the ratio constant.
一个比是5：7，如果比的前项增加35，要使比值不变，比的后项增加多少．
<gadget id="calculator">7 * 8</gadget>
<output>56</output>

<gadget id="calculator">56 - 7</gadget>
<output>49</output>

<result>49</result>