Interesting question in ancient Russia: A hired worker’s annual salary is 12 rubles plus a robe. When he left after working for 7 months, he just paid him a robe and 5 rubles. What is the price of this robe?
俄罗斯古代趣题：一个雇工每年的工钱是12卢布加一件长袍，他在工作7个月后离开时，恰好付给他一件长袍和5个卢布，问这件长袍的价格是多少？
<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">12 * (7/12)</gadget>
<output>7</output>

<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">1 - (7/12)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">2 / (5/12)</gadget>
<output>24/5 = around 4.8</output>

<result>24/5 = around 4.8</result>