The customs building has twelve floors. Li Ping’s father works on the tenth floor. One day, Li Ping went to find her father. She walked from the first floor to the fifth floor in 40 seconds. Arrived at her father's office.
海关大楼共有十二层，李苹的爸爸在十楼办公，有一天，李苹去找爸爸，她用40秒从一楼走到五楼，照此速度，她至少还要再走多少秒才能到达她爸爸办公室．
<gadget id="calculator">40 / 4</gadget>
<output>10</output>

<gadget id="calculator">10 * 5</gadget>
<output>50</output>

<result>50</result>